Well RNGs in those days were notoriously bad. I remember for a long time having difficulty deciding how save scumming really worked. I believed for a long time that certain actions reset the number seed while actually reloading did not, but I never managed to narrow down any particular actions. All in all, I have to say that through extensive save-scumming "research", I found that the seed apparently does not reset at all but still advances 1-2 stages. Funny thing is, it'll get the same response multiple times in a row almost every time.
Anyway, yes the RNG was definitely broken but I don't believe that can account for how many times cannons brought power sources intact vs. stringrays and avalanches not doing it, with zero deviation.