I've had fish survive the "I was in the vortech basket when the power came back on" thing. They loose some scales but survive, assuming good overall health and decent water. Snails too, although they are capable of physically blocking impeller rotation, which is not good. Blinking vortech controller error codes.
I can hear when snails try to enter the basket when the pump is on. Sudden impeller whacking something sounds. Most snails crawl away. The occasional idiot keeps going, causing the previously mentioned vortech blinking.