I suspect everyone will be playing this one with a very straight bat. Certainly given the threat (empty or otherwise) of an AFP investigation.
I'm sure the recorders will be just fine. The AF447 recorders were OK after a crash which caused the aircraft to disintegrate and killed all on board, and after several years at a depth of 4000 m. So these recorders will be just fine after a ditching that all survived, and after a couple of years at 40m. I don't think the ATSB need lay awake at night worried the data on the recorders will be unrecoverable.
Just to be sure however, the recovery (of the recorders, and of the data from the recorders) should be overseen by someone from an external agency like NTSB, or even the French (never thought I would be saying that).