There was the report of a (panicked?) passenger opening a rear exit when it was partly under water. Perhaps the FAs, if uninjured, should immediately "guard" exits that should not be opened. Of course they have to facilitate the evacuation of the aircraft, but there may need to be some effort at directing passengers at "what not to do." Since there are not really any seconds to spare in an evacuation it would be difficult to make any changes. Fortunately the procedures worked well in this case as it also did in other incidents like with AF flight 358 in YYZ in 2005.