Proving this would be nearly impossible unless irrefutable proof emerges, ie. an email that says “we can’t hire this person for this role for no other reason than they stutter.” And this is pervasive across every industry. It’s the reason the “Must be able to lift 50 pounds” is still included in so many job requirements regardless of actual job duties. It’s meant to weed out the “undesirables” with disabilities while hiding behind a legal argument. Never forget that when it comes down to it we’re all just a number in the corporate world. Don’t take it personally.