I find it quite incredible that anyone can be so - er - imaginative as to thinking they could see explosive bolts fire (items maybe 20=30cm long?) in a video where a thing the size of a skyscraper is only wobbly-viewed in fuzzy full-frame from end-on...
As to how one can assume failure of a 'water deluge"... Do they have one? Where are the water towers? Not visble anyway. Isn't that why the stack is fired off a raised platform? And by what physics could debris possibly manage to return into an engine against that phasmagorical maelstrom of thrust? It's not as if it's an atmospheric engine breathing ambient air full of debris is it? Any debris from spalling concrete (which one would imagine the dimmest of SpaceX engineers would have thought of...) would simply be blown into the next county.
Sorry, just no.