I'm trying to understand if there is a situation where driving into a red and white stripe with flashing lights on it is correct. Does the Tesla think that because there isn't anything below the crossing arm, that the arm is actually farther away? Or it looks vaguely similar to the back of a trailer, but not enough so that is ignored?

Yeah I'm wondering the same, is the just ... baseline obstacle avoidance somehow being bypassed or failing? Those arms are right there.

It's very strange. Even if it doesn't see it as a RR crossing, there's arms right there.