Roe Boat, LLC v. N & G Engineering, Inc., 0:19-cv-61503

Roe Boat LLC alleges a July 26, 2017 onboard fire was caused by N&G Engineering’s faulty repairs to the vessel’s starboard turbocharger and related work.
Plaintiff disclosed affirmative liability expert Michael Hill (opining a coolant overflow hose likely ignited from hot-surface contact and ceiling insulation as another potential source).
Defendant disclosed liability expert John Toth, who rebutted Hill’s cause-and-origin opinions, faulting the hot-surface ignition theory and opining the fire initiated inside the exhaust riser due to turbo oil-seal failure.
Plaintiff then designated Bryan Emond as a rebuttal expert to reply to Toth; Defendant moved under Rules 26 and 37 to limit Emond’s testimony as exceeding rebuttal scope.
The magistrate judge granted the motion in part, striking two Emond opinions: (1) that rigorous temperature calculations were unnecessary to assess ignition (Opinion One), and (2) that considering ceiling material near the exhaust riser was unnecessary because the riser was aft of the origin area (Opinion Two).
The court applied Rule 26(a)(2)(D)(ii) standards (rebuttal must address the same subject matter) and Rule 37 exclusionary principles for undisclosed or improperly designated expert opinions.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Scope of rebuttal: necessity of temperature calculations (Opinion One)	Emond rebuts Toth by explaining physical characteristics make ignition probable and that detailed temperature calculations are unnecessary.	Toth never criticized Hill for lacking temperature calculations; Emond’s opinion supplements Hill’s affirmative case rather than rebutting Toth.	Stricken: Opinion One exceeds rebuttal scope and improperly supplements Hill’s report.
Scope of rebuttal: need to consider ceiling insulation (Opinion Two)	Emond contends ceiling material need not be considered because the exhaust riser is aft of the identified origin, contradicting Toth’s initiation-inside-riser theory.	Toth did not address ceiling materials; Emond’s discussion fills a gap in Hill’s affirmative case rather than rebutting Toth.	Stricken: Opinion Two does not rebut Toth and improperly bolsters plaintiff’s case-in-chief.

Guevara v. NCL (Bahamas) Ltd., 920 F.3d 710 (11th Cir. 2019) (timing and sequence of expert disclosures under Rule 26 govern rebuttal designations)
OFS Fitel, LLC v. Epstein, Becker & Green, P.C., 549 F.3d 1344 (11th Cir. 2008) (Rule 37 exclusion applies to undisclosed expert testimony unless substantially justified or harmless)
Mitchell v. Ford Motor Co., [citation="318 F. App'x 821"] (11th Cir. 2009) (burden rests on non-disclosing party to show substantial justification for Rule 26 violation)
Marmo v. Tyson Fresh Meats, Inc., 457 F.3d 748 (8th Cir. 2006) (rebuttal evidence may not be used to establish a party’s case-in-chief)
Cates v. Sears, Roebuck & Co., 928 F.2d 679 (5th Cir. 1991) (distinguishing proper rebuttal from supplemental affirmative proof)