Eastern ATC may have a point. In a lot of crashes the coaxial cable from the ELT to the fuselage mounted skin gets severed. The unit works fine after the crash but there is no antenna connection, so transmission is only for a few hundred feet, if that. In a water crash that is not too severe one second or so of ELT transmission before the cable is severed would not be out of the ordinary. If the aircraft hit a vertical rock face on a peak in Tibet, then no.