[944Spec_bound]

I wonder what the horrendous squealing was though? If that bolt was just bouncing all around in there, I'd expect alot of rattling and banging, but if it was squealing it must have gotten pinched between a belt and something, hopefully not a roller or gear. From the looks of your balance belt, it was probably just wedged between the timing cover and the belt.
I'd be double sure the only damage was to the balance belt, and triple sure I torqued all the bolts.

I'd rather be lucky than smart.