Don't beat yourself up. I'm a horrible dog parent. Brutus and Ruthie have some manners but they do act out sometimes on walks....especially if they sense something like don't like or another dog I know they won't like. I would trust my dogs instincts on a person better than i would my own. That mans walker probably freaks them out too since it's not something they are used to seeing.
I personally don't think anyone has it "all together", so just keep your head up and maybe work with them a bit more!