Anyway, my anecdote: we were interviewing for a C developer position. The next candidate was in his 50s. Our project leader took a dislike to him the moment he saw his resume. No idea why but I assumed it was either his age or that this project leader knew him and didn't want to work with him for some personal reason.

The project leader arrived to the interview at least 40m late. In that time this candidate impressed me (as the C guy) very much and I said 'hire' immediately. However, as presaged, the project leader said no.

This candidate had no way of knowing what had happened. He definitely could tell I was impressed so he probably assumed it was his age. Just imagine how he must've felt. I probably should've contacted him to let him know how messed up the our process was.