There are any number of reasons why the floats did not inflate....some of which have nothing to do with complacency, pilot error, forgetfulness, or human error. As any experienced helicopter pilot or engineer knows....things that are supposed to go "pop"..."Swoosh"....sometimes do naught....or half naught.
Perhaps we should wait to hear from reliable sources what the cause of this lack of flotation was caused by.
Perhaps we can get Lappos to R and D us a boat hulled single engine Bell helicopter....thus floats would not be an issue. Wait a minute....Sikorsky already did that years ago!