from a friend of mine :
I do disagree with the “Kamtza v. Bar-Kamtza” comparison. (Besides the obvious, common, error that they 2 hated each-other. Kamtza wasn’t the host. And he and Bar-Kamtza might have never even met.)
It seems that the Host hated Bar-Kamtza on a personal level. Not Stam cause he was a Tzidoki. And the sin wasn’t that he wasn’t invited. The Aveira was that after he was there already, and it was due to an innocent mistake, he tossed him out “Bifnei Kahal V’Aida”!
Yes, if the Vizhnitzer Rebbe attends and Rabbi Lau suddenly shows up and they have him chucked out, (or even if at that point the Vizhnitzer Rebbe demonstratively leaves) that would be different! That would be very wrong. And the Rebbe would, of course, never do that.