To be crass, I threw this person on the schedule and gave them a deadline with every intention of removing them the next day to shut them up so I could go to sleep. The LT schedules change up to and during the event itself and I've rejected a lot of talks once it was clear that the slides or revisions contained inappropriate material.
The goal of the event is to give everyone a chance to take the stage, the point is to not curate beyond clustering similar topics together. People sing songs, do dances and any number of crazy little things and sometimes will blow you away with an amazing idea.
That being said, I started training my potential replacements for the LTs at the 30c3 for the reasons you stated, among others.
I believe today, the talks are assembled by a team of three people with each person taking the helm on a particular day.
This doesn't excuse the level of JA's alleged continued hostility, but this is an example of why, for conference-level situations, talks and topics should be discussed by a group of people, rather than just having one person make the decision. I could see why a talk accusing JA of being an informant might be funny in a close-knit group, but it sounds like people actively hated JA by this time, and this conflict, combined with the paranoia that is probably natural in this field, would add to JA seeing this as an aggressive act of hostility. With one decision-maker who has a quirky sense of humor and/or more laid back attitude, such a talk could seem harmless. But I think if another person had been part of the talk-filtering process, they would've seen the proposed talk as unnecessary antagonism.
But while JA had a right to be angry about the proposal, that doesn't justify harassing Farr, or demanding the private details of the proposer, or obviously, any of the other allegations against JA. Good for Farr for standing up for the privacy of the individual who proposed the talk.