I am surprised it can go up that high because the other screenshot of 65535 was at maximum unsigned integer limit.
Yeah, it used to be 16 bit unsigned int, but they apparently changed that, because 2^32-1 = 4294967295, so now that is 32 bit unsigned int max.
i think the bug itself comes from the fact that its initialized somewhere as -1, which would be 65535/4294967295 if sign is lost.