What standard of review governs our review of whether a credit is a coupon within the meaning of CAFA?

^5. As in In re Online DVD, we need not decide which standard of review governs our review of whether a credit is a coupon within the meaning of CAFA, because here the district court applied the wrong legal rule when evaluating whether the credits qualify as coupons. See 779 F.3d at 950 n.8 (explaining that it was unnecessary to decide on the applicable standard of review because we would affirm under any standard). Failing to identify the correct legal standard constitutes reversible error even under abuse of discretion review. See Enyart v. Nat'l Conference of Bar Examiners, Inc., 630 F.3d 1153, 1159 (9th Cir. 2011).