In Gittin 55b-56a, we read that a fellow named Bar Kamtza was humiliated by a host of a party in public view of all, including the rabbis. Bar Kamtza received an invitation to the party by mistake, but did not know of the mistake, and assumed that the host was ending an old feud. Bar Kamtza suggested numerous compromises to avoid humiliation, but his host accepted none, and threw him out on his ear.
Bar Kamtza then said to himself: “Since the Rabbis were sitting there and did not stop him, this shows that they agreed with him. I will go and inform against them to the government.” He then plotted to put the rabbis into a situation where they would have to choose between violating halacha and upsetting the Romans. They chose the latter course, and this, the Gemara says, led to the siege of Jerusalem and its eventual destruction by the Romans.
Question: How do the commentators view the apparent silence of the rabbis during Bar Kamtza's humiliation? Did they actually witness the event? If they did, did they have a duty to intervene and stop the host? Do any commentators take the rabbis to task for their silence? Sorry to ask multiple questions, but I think they are all related and relevant to us today.