Plaintiff Jonathan Conner is a Jones Act seaman who worked for REC Marine aboard the M/V GOL Warrior. While working aboard the vessel, he suffered what was later diagnosed as a heart attack at some point in the day on January 27, 2024.

Conner alleged that REC Marine was negligent in its handling of his medical emergency and that the vessel was unseaworthy because the crew lacked the training and preparation required to respond appropriately to the medical emergency.

REC Marine filed motions to exclude and/or limit the testimony of two of Plaintiff’s designated experts—Captain Christine Hafen, Plaintiff’s marine liability expert, and Dr. Xianfeng Wen, one of Plaintiff’s treating physicians who is presently designated as a non-retained medical expert pursuant to Rule 26(a)(2)(C) of the Federal Rules of Civil Procedure.

Maritime Expert Witness

Captain Christine Hafen possesses over 25 years of experience in maritime and offshore drilling, including roles as a ballast control operator, dynamic positioning operator, captain and chief mate.

Discover more cases with Christine Hafen as an expert witness by ordering her comprehensive Expert Witness Profile report.

Cardiovascular Diseases Expert Witness

Xianfeng Wen earned his medical degree from Shanghai Medical College of Fudan University in Shanghai, China. To begin with, he completed his residency in internal medicine and fellowship in cardiovascular disease at the University of Texas Medical Branch at Galveston where he served as chief fellow.

Board certified in cardiovascular disease and comprehensive echocardiography, Wen has practiced medicine since 2007. Moreover, he has extensive training in different aspects of cardiovascular care including non-invasive and invasive cardiovascular evaluation, advanced cardiovascular imaging and peripheral arterial and venous diseases.

Want to know more about the challenges Xianfeng Wen has faced? Get the full details with our Challenge Study report.

Discussion by the Court

a. Marine Liability Expert—Captain Hafen

REC Marine wished to exclude Hafen’s expert report and untimely report
supplement. Defendant’s principal argument is that the first two sections of Hafen’s report are inadmissible because she based those opinions on REC Marine’s alleged lack of compliance with the International Safety Management Code (“ISM Code”), a set of regulations that arguably does not apply as a matter of law to the vessel Conner worked on.

Because the M/V GOL Warrior did not fall into the category of vessels that are required to be in compliance with the ISM Code, REC Marine argued that the ISM Code is wholly inapplicable to this matter and thus rendered Hafen’s opinions unreliable since they rested on irrelevant safety standards as applied to this vessel. Additionally, REC Marine wished to exclude the third section of Hafen’s report because it inappropriately provided legal opinions on the Receipt & Release Agreement, which REC Marine argued went outside of the bounds of appropriate testimony for a marine liability expert. It also sought exclusion of her supplemental report that was untimely submitted on March 31, 2026—just over two months after the deadline for Plaintiff to produce his expert reports.

Analysis

1. Opinions Based on the ISM Code Are Permissible.

The Court found that her expert testimony, reliant upon a seemingly widely accepted set of safety standards, provided the kind of specialized analysis that will assist the trier of fact in understanding the evidence in this case. REC Marine may challenge Hafen’s reliance on the ISM Code in cross-examination. And of course, the Court retained the ability to limit or control the scope of her testimony at trial. Overall, the Court will not limit or exclude Hafen’s testimony insofar as she pointed to the ISM Code in support of her conclusions.

2. Opinions About the Receipt & Release Are Inadmissible

REC Marine presses that the third section of Hafen’s expert report, which addressed the Jones Act, should be excluded both because it impermissibly reaches conclusions of law and because it goes beyond the scope of her expertise as a marine liability expert. The Court agreed. Moreover, Plaintiff “did not contest REC Marine’s motion to the extent it sought to prevent Hafen from opining concerning whether Conner’s release was consistent with the Jones Act.”

3. The Supplemental Report Is Excluded, Unless Used for Rebuttal

REC Marine asked the Court to exclude Hafen’s supplemental report because it is not a true supplement and instead contained new opinions and analyzed new data; thus, it should be excluded because it was disclosed over two months after Plaintiff’s deadline to provide his reports.

The Court reviewed the report and found that it went beyond the scope of Hafen’s initial report and is not a mere supplementation to her timely-disclosed expert report. Importantly, the data analyzed in the supplemental report is publicly available and thus was not “unavailable to” Plaintiff nor Hafen at the time of her initial report.

However, the Court noted that Hafen’s supplemental report was issued on March 31, 2026—within the 30-day rebuttal report deadline provided for in Rule 26(a)(2)(D)(ii). That rule provided that an expert disclosure must be made “within 30 days after the other party’s disclosure” so long as “the evidence is intended solely to contradict or rebut evidence on the same subject matter identified by another party under Rule 26(a)(2)(B) or (C).” To the extent Hafen’s report operates as a rebuttal report to Defendant’s marine liability expert’s report concerning the interpretation of AIS data, the Court will exercise its discretion at trial to allow Hafen to testify as to her supplemental report in this limited way, i.e., as a rebuttal report, if Defendant’s expert’s testimony addresses these issues.

B. Wen’s Testimony Will Be Limited

Wen is properly designated as a non-retained expert and therefore falls within the parameters of Rule 26(a)(2)(C), absolving him of the written report requirement of Rule 26(a)(2)(B). The only question this Court considers is the appropriate scope of his testimony.

1. Compliance With Rule 26(a)(2)(C)

While the disclosed topics are the sorts of subject matters district courts tend to allow treating physicians to testify about, the disclosure is completely silent as to the facts relied upon by Wen in forming his opinions, except for reference to his records.

The Court agreed that mere reference to the medical records, without more, is insufficient to satisfy Rule 26(a)(2)(C)’s disclosure requirement because “ the question is not the level of specificity required in the summary, because Plaintiff has failed to produce any summary of the facts and opinions to which Wen is expected to testify.”

Testimony from a treating physician is certainly important evidence. However, considering that Plaintiff has a retained medical expert who has seemingly issued a timely report that touches on causation and future treatment, it is less important for Plaintiff’s treating physician to testify about causation and future treatment. Prejudice to REC Marine is most likely minimal, and REC Marine raised no prejudice arguments in its briefing. Furthermore, Defendant had the opportunity to take Wen’s deposition and, if it did, glean his perspective on causation and future medicals from his vantage point as a treating physician.

Overall, the Court will not exclude the defect in Plaintiff’s Rule 26 disclosures
for Wen because such defect is most likely harmless to REC Marine.

2. Duplicative Expert Testimony Under Rule 403

Defendant cited no case wherein a district court has excluded a second medical causation or future medical treatment opinion as cumulative pursuant to Rule 403. As such, the Court will not, at this time, restrict Plaintiff from calling both a retained expert who specifically produced a report on causation and a non-retained expert who may be able to testify as to causation if his opinions are based on his personal treatment of Conner and nothing more.

Held

The Court granted in part and denied in part the motions to exclude and/or limit the testimony of Captain Christine Hafen and Dr. Xianfeng Wen.

Basically, the motions were granted to the extent that Hafen (1) may only testify as to her supplemental report if it can be properly considered a rebuttal report under Rule 26(e), and (2) may not testify as to the Receipt & Release Agreement. The motions were denied with prejudice as to Hafen’s opinions based upon the ISM Code.

Also, the motions were denied without prejudice as to Xianfeng Wen’s testimony as a non-retained expert.

Key Takeaway

Rule 26(e) allowed the supplementation of a disclosure, such as an expert report, “in a timely manner if the party learns that in some material respect the disclosure or response is incomplete or incorrect.” But supplementation is not limitless; courts have found that “expert reports may only be supplemented in limited circumstances, specifically where supplementation ‘means correcting inaccuracies, or filling the interstices of an incomplete report based on information that was not available at the time of the initial disclosure.’”

Case Details:

Case Caption:	Conner V. Rec. Marine Logistics, Llc
Docket Number:	2:25cv458
Court Name:	United States District Court, Louisiana Eastern
Order Date:	April 21, 2026

Category: Cardiovascular Diseases Expert Witness

Maritime Expert Allowed to Opine on Safety Standards

Maritime Expert Allowed to Opine on Safety Standards