I'd switch off - unless there was immenent danger to the craft - and therefore the MOB by not switching off
thats right as far as I'm concerned. No good dragging one into the boat and then drowning everyone on the rocks.
Our dive club never stopped the motor once out at sea in case it wouldnt start - but thats a long time ago and shouldnt be the way now with modern equipment.
My dive buddy had his mask smashed and forehead cut by a propeller that was on the club outboard which was allegedly in neutral. Prop just turning as they often do in neutral was the explanation. Well perhaps it was, perhaps it wasnt but the helm certainly wasnt going to admit to anything that might have been his fault. Impressive scar - he used to crack on it was a duelling scar.