Yes, I agree. I always thought that's why he did that. "If you can't pass for human you're not much good to us."
As for leaving the scene after the police arrived, that part is a little more difficult to make sense of. Because he was damaged and looked inhuman? He didn't leave after the truck ran him over and half his face was gone ("get out"), even though he looked inhuman, presumably because his target was within his range and killing his target was apparently more important than maintaining his cover. So I always wondered why he left when the police came. Best I can come up with is that his hand must have been damaged to the point that it was useless so repairs were absolutely necessary. Still makes you wonder why he didn't just hold the gun with his other hand.
OK, DiFabio, you and I are good at this sort of thing. Can we come up with an internally consistent explanation for why he left the scene after the police arrived?
Hmmm . . . maybe if the police had seen that he was a machine, it would blow his cover, but if some random truck driver saw it, it wouldn't matter as much?