When I do feel bad, the things I remember are this,
a) The issue that they were all a part of the same discord and watching more animal abuse than just the hamster
b) The bullying of that student with that photograph of all of them holding hateful messages,
c) The plans to first frame fiona likely being discussed in that discord, and then to frame zoe being discussed in that discord as well. At some point, everyone involved likely saw that and had to ask themselves "will I be keeping my mouth shut". If Allen or someone else wanted to report it to the Dean, came here, gave proof, wanted off the ride, released all their files, cooperated with the university, kiwis, or whomever- I'd have more pity.
d) With the previous school investigation launched on Louis and Bella, at that point, anyone involved with either of them should have cut ties, jumped ship, and never talked with them again. Some of the smarter ones likely did. When something like that happens, throw as much distance as possible between you and these kinds of people. Allen still being in the chats, talking about CwC (or, according to him "no, its actually Bella's cousin Chris, not Chris-chan, and we were joking about him being suicidal over soccer"), and being witness to a lot of this stuff is the opposite of that.
The people I feel the most sorry for would probably be these kids parents. Allen was also trying to convolute the facts with people he talks to, downplay involvement, and otherwise seemed to be digging his own holes as well.