Is it safe to use a bike tire that was on a wheel that got tacod? My bike recently got into a crash (I was not on it) and both wheels were taco'd. Is it safe to take the tires off and use them on a different wheel?
What could go wrong and what should I look out for?
It should be perfectly safe to re-use the tyres.  Many tyres are stored folded/twisted in their packaging to save space.

I would however recommend carefully inspecting each tyre first, checking for damage to the tread area, sidewalls and tyre bead.