Hmmm...
Mostly people in the past talked smack, but walked out when offered a senior student or any kind of response.
The US doesnt really see this much in general.
When I was practicing Kempo, we would have an open sparring night. Anyone could come in and bang with us. Often they would complain that we were far too heavy on contact. It would take time, but eventually they came to understand that what they were experiencing was 'light contact' or 'incidental contact'.
This would change their frame of reference and challenge the assumptions regarding their practice.
One gentleman who visited quite regularly became obsessed with matching with me every time he was in. He always tried to hit me as hard as he could. I think it was an ego bruiser for him that I simply ignored his hand technique altogether.
If people come in to the kung fu school these days, there is always room for discussion regarding an exchange of ideas, as far as I know.
Much better to make a friend than a corpse.
Rob