"The Justices ... focused on whether the plan established a reimbursement agreement or a merely a right to subrogation.... Freestanding subrogation claims have one set of remedies or rights, and subrogation claims by agreement have another. Justice Sotomayor found 'unsettling' McCutchen's suggestion that the rights and remedies would be the same for express and implied agreements.... Several Justices ... also were concerned with the perceived unfairness of the plan's ability to seek reimbursement of the entire amount obtained from the third party without factoring in attorney's fees.... The argument also featured a heated exchange between the Justices over an issue that McCutchen did not raise on appeal -- the distinction between the language in the summary plan description and the formal plan document.... It thus is possible that the Court will revisit its Cigna Corp. v. Amara decision on the primacy of plan terms."