i have trouble believing this tbh
highly unlikely (unless you were drunk) that you wouldn't react and be able to leap from the collapse
even more unlikely is the floorboards, joists and vinyl flooring covering (or whatever it may be covered by) being so susceptable in one point that you actually fell through
if there had been a water leak over a period of time long enough that it had managed to rot the timbers, the tell tale signs would have been there; you'd have seen it on the ceiling of the room below, you'd have heard it, you'd have smelled it, you'd have notcied it when the floor was trodden on and it is more likely that only your foot would have gone through a board that was rotten
not saying it can't happen but without photographic evidence, i do find it hard to believe. i mean, come on, the joists went, you fell (say) 2 metres and you only had a few cuts and bruises? count yourself lucky if this is a true story