"I told you, civic duty. I took a couple of people to the hospital and saw you working there."
Bill reached for his pack of cigarettes and tapped the package repeatedly against the palm of his other hand. He was waiting until he reached the comfort of his own home so he could begin to smoke.
"Everyone looked very busy. I just didn't want to get in anyone's way."
Translation: you probably didn't notice me. It was plausible that Bill might have seen the doctors at work with out them seeing him in return.