Like you said it would be hard to prove. That said, I don't think anyone is holding a stutter against us. It's all about who's better for the role. If myself and John Doe are both applying for the same sales job, with the exact same qualifications and personality, but he doesn't stutter, he's probably going to get it. That's just how it is. Accepting that and making ourselves more knowledgeable in the work field greatly increases our chance of being hired.