And what do the 'plenty of rules' already say about minimum altitudes for single engine commercial operations over water? From the OP, the two aircraft were estimated to be at 4000 feet, in the dark, beyond gliding distance from land.
The days of a 'gung ho' culture in aviation have gone forever. Today people litigate when bad **** happens, even when they contribute to that bad **** either through ignorance or stupidity.
Engine failure? Sue the manufacturer, MRO and whoever signed the last maintenance release. Ditched and flipped inverted/sank? Sue the designer, builder, instructor and flight organisation who hired the thing out. Drowned? Rellies sue the rescue organisation for not being instantly on the crash site.
GA is already in destruct mode, without pilots being encouraged to take unnecessary risks. Every time people die in light aircraft accidents it hastens that demise.
Btw although the years finally made me risk-averse to over-water in bugsmashers, I still ride a motorcycle, knowing that statistically the motorcycle is the more dangerous. But at least I am fully informed, which may not have been the case with those student pilots.