Sammygol,
What a horrible story!
Aside from the fact that the Rav (despite his statement to the contrary) DID, in essence, call thousands of Jews who follow their rav m’challelei shabbos, he also chose to publicly humiliate this potential witness. Even if the Rav truly had a legitimate problem with the potential witness, this is the type of thing that you take care of in private, not in the presence of others*.
The Wolf
* As proven by the fact that sammygol was there. The only reason for the rav to do this to someone else in front of sammygol is if he was the chosson, kallah, one of the parents or the other potential witness — which, from his description, does not seem to be the case.