We were taught to assess probability (how likely something was to
happen) and hazard (how severe the problem would be if it happened).

Well, arguing probability doesn't make a shred of sense when you're talking
about a simple situation like this one. Effectively hard-wiring a live
electrical cord on a pier is both stupid and a violation of the electrical
code, not to mention common sense. Choosing this as a foundation for
arguing logic doesn't make much sense.