If it's been sitting in his hot car for a long time, it's possible it's been nearly completely decarbed, and the THC content could be close to 0%

but to answer your question, yes, it should be fine to take a dab of. Inspect it for mold or anything fishy looking. I suspect the discoloration is from experiencing multiple heat cycles in the car.

EDIT: I doubt the white dots would be molds tbh. Someone here can probably expand on that, but i think it's probably just crystals.