Aha okay, so I think is an edge case. I don’t have looped set. If you turn looped off and play the animation, it won’t play at least once, which is the main issue here, and that is the actual bug. Playing an animation, whether it is looped or not, I reasonably expect as a user, for it to actually play that one time 
I understand that because it is a rate scale of -1.0, it is hitting a condition that is checking if frame==endframe and stopping immediately, which is incorrect. Looping is not an option for me because I want to programmatically check for the finish of the animation and play a different one, -1.0 or otherwise. So yeah, this is still a bug for me.