As described here, passenger claims against Asiana Airlines are limited by the Montreal Convention. But any claims the victims’ may have against a manufacturer of the aircraft or its component parts are not.
NTSB Chairman Deborah Hersman reported that evacuation slides opened inside the passenger cabin. The slides are, of course, designed to open outside the cabin. Passengers (or crew) who were injured by the slides may be entitled to compensation for those injuries from the appropriate manufacturers, if it is proven that the slides malfunctioned because of a defect rather than an error on the part of the flight crew. Those sorts of claims would be governed by U.S. product liability law, not by the Montreal Convention.