Before CLEMENT, ELROD, and DUNCAN, Circuit Judges. STUART KYLE DUNCAN, Circuit Judge: This byzantine dispute arises out of a catastrophic oil well blowout that occurred in 2013 on the HERCULES 265 drilling rig in the Gulf of Mexico. The rig’s charterer brought products-liability claims against a refurbisher of the rig’s blowout-prevention components, setting off a cascade of counterclaims and third-party claims based on various indemnity provisions in the web of contracts among the parties. Eventually, the district court granted a series of summary judgments, based both on contractual indemnity and also on the merits of the liability claims. For the reasons discussed below, we AFFIRM in part, REVERSE in part, and REMAND for further proceedings. I. We here provide a sketch of the background facts and proceedings. We dive later into deeper detail as needed when addressing specific issues. Axon Pressure Products, Inc. and Axon EP, Inc. (together, “Axon”) manufacture and service equipment used in offshore oil rigs. In 2010, Axon was hired by non-party Seahawk Drilling, Inc. to work on equipment on the rig that would eventually feature in this case—the HERCULES 265 drilling unit. Axon refurbished and remanufactured various parts on the rig designed to help prevent well blowouts. In 2011, Hercules Drilling Company, at that point the owner of the HERCULES 265, entered an Offshore Daywork Drilling Contract (the “Drilling Contract”) with Walter Oil & Gas Corporation. Under that agreement (as later amended), Walter chartered the HERCULES 265, located in the Gulf of Mexico. Hercules provided the rig and crew to Walter for re-working the A3 well, located about 84 miles south of Houma, Louisiana. The Drilling Contract contained various provisions allocating liabilities between Walter and Hercules. In 2013, a blowout occurred at the A-3 well that the crew was unable to contain. Oil, gas, and other materials blasted up through the well at dangerously high pressure. The blowout caught fire and burned for several hours before sealing itself off, in the process causing extensive damage to the rig and other property. As required by federal law, Walter assembled a team of independent well-control experts to investigate the incident. The experts eventually produced multiple reports suggesting that human error led to the blowout. Walter incurred over $70,000,000 in expenses resulting from the blowout. It tendered various claims to its insurers, Certain Underwriters at Lloyd’s, London and Certain Insurance Companies Subscribing to Policy Nos. JHB CJP-1861, JHB CJP-1959, and 13PKGN9161 (together, “Underwriters”). Underwriters paid out over $48,000,000 in claims to Walter. Walter and Underwriters (as a subrogee of some of Walter’s claims) then sued Axon.[1] Walter asserted products-liability claims against Axon, alleging that the parts it had worked on malfunctioned, causing the blowout. Tana Exploration Company and Helis Oil & Gas Company—which both owned non- operating working interests in the A-3 well—also sued Axon. (Together, we refer to Underwriters, Walter, Tana, and Helis as “Plaintiffs.”) In response, Axon filed counterclaims against Walter for indemnity as a third-party beneficiary under the Drilling Contract, as well as a breach of contract claim against Underwriters as a third-party beneficiary of Underwriters’ promise to release claims against anyone Walter had released from liability. Axon also brought a third-party complaint against Hercules.[2] Axon asserted that it was the failure of Walter or Hercules personnel to operate the rig correctly that caused the blowout. Axon sought defense, indemnity, and attorney’s fees from both Walter and Hercules. In response to Axon’s lawsuit, Hercules tendered its defense and indemnity to Walter, asserting that Walter had contractually assumed the liabilities Hercules then faced as a result of Axon’s claims. Walter did not respond, and later moved for summary judgment on the issue. It sought a declaration that it did not owe defense and indemnity to Hercules for Axon’s claims. In response, Hercules filed a third-party complaint against Axon and Walter. It sought indemnity and contribution from both. The parties moved for summary judgment on various issues.[3] Axon sought a ruling that Hercules owed Axon indemnity for all claims by Walter and the other plaintiffs. The district court granted the motion and held that Hercules was obligated to defend and indemnify Axon for any losses from Plaintiffs’ claims. Axon also moved for summary judgment against Plaintiffs on the substance of their products-liability claims. First, Axon contended that Plaintiffs failed both to prove causation and to show that Axon’s products were defective. Separately, Axon asserted that Plaintiffs failed to produce evidence of damages. The district court eventually granted each of Axon’s motions, though it did not provide a reasoned opinion for some of its decisions. Hercules moved for summary judgment, seeking a ruling that Walter was required to defend and indemnify Hercules for any losses resulting from Axon’s claims against Hercules. The court granted the motion. To sum up: an oil well blowout caused millions in damage. Plaintiffs sued Axon for products liability. Axon then counterclaimed against Plaintiffs and brought a third-party complaint against Hercules. Hercules then brought a third-party complaint against Axon and Plaintiffs. The district court granted summary judgment on various indemnity and merits issues and also struck several expert reports and evidence, with Axon winning on most issues. Plaintiffs and Hercules now appeal different decisions by the district court. Plaintiffs appeal the grant of summary judgment in Axon’s favor on the merits of the products-liability claims. They also appeal the district court’s decisions striking various expert reports and evidence. Walter appeals the district court’s decision that it owes a duty to release and indemnify both Hercules and Axon. Hercules appeals the court’s determination that it owes duties to defend and indemnify Axon. II. We review a grant of summary judgment de novo, applying the same standard as the district court. Rogers v. Bromac Title Servs., L.L.C., 755 F.3d 347, 350 (5th Cir. 2014). “Summary judgment is proper ‘if the movant shows that there is no genuine dispute as to any material fact and the movant is entitled to judgment as a matter of law.’” Id. (quoting Fed. R. Civ. P. 56(a)). A genuine dispute of material fact exists “if the evidence is such that a reasonable jury could return a verdict for the nonmoving party.” Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 248 (1986). “We construe all facts and inferences in the light most favorable to the nonmoving party,” Dillon v. Rogers, 596 F.3d 260, 266 (5th Cir. 2010) (quoting Murray v. Earle, 405 F.3d 278, 284 (5th Cir. 2005)), but “[s]ummary judgment may not be thwarted by conclusional allegations, unsupported assertions, or presentation of only a scintilla of evidence,” McFaul v. Valenzuela, 684 F.3d 564, 571 (5th Cir. 2012). Finally, “we are not limited to the district court’s reasons for its grant of summary judgment and may affirm . . . on any ground raised below and supported by the record.” Boyett v. Redland Ins. Co., 741 F.3d 604, 606-07 (5th Cir. 2014) (cleaned up). We review the exclusion of expert testimony for abuse of discretion. Sims v. Kia Motors of Am., Inc., 839 F.3d 393, 400 (5th Cir. 2016). “A district court abuses its discretion if it bases its decision on an erroneous view of the law or on a clearly erroneous assessment of the evidence.” CenterPoint Energy Hous. Elec. LLC v. Harris Cty. Toll Rd. Auth., 436 F.3d 541, 550 (5th Cir. 2006) (quoting Ross v. Marshall, 426 F.3d 745, 763 (5th Cir. 2005)). III. We turn first to the various indemnity issues. The parties’ indemnity obligations are governed by a web of contracts. This simple diagram outlines the contours of those contractual relationships:
