Ask yourself why you did it in the first place. There was no reason for you to let them out other than you wanted the moral satisfaction of getting that wave or nod. You can claim it’s because you were trying to be nice, but you even admit that it made it longer for the other person and you seem to have known this before you let them out. What I think is ridiculous are people that expect an acknowledgment like you are for something so mundane. Just drive your car and get a pet if you need some attention.