Interesting thoughts! Ok, my "its a movie" thought was just that this is something the movie-makers wanted us to know about Clint, so they had Loki say it as if he had precognition, but really the point was for us to be like "oh, this Hawk-guy has heart."

Your point about reading people quickly is a good one. I hadn't thought about that. I was just thinking they must have been doing background checks before dumping Loki b/c it seemed like he chose the right man for the job.