True, we only have Jill's first hand account of it, but I think she's more trustworthy than most, if not all the DIK members. Jill, so far, has been pretty open toward MC overall. Rusty, and other DIK's are more self centered and care about their image/ego more than other characters (from what I've seen/noticed).
Then again, in my playthrough, I'm not necessarily (personally) allied with the DIK frats, I personally line up with Chik affinity/Chik for the Maya/Josy storyline.
As long as the maya/josy storyline doesn't get f'd with some crazy drama I don't care about the rest...
Edit: I know there's something that Jill and Bella are hiding, they obviously have serious history and her husband left after some altercation. Likely Bella cheated on him with another teachers husband. I also wonder if Bella and Jill are related, given the picture you find in Jill's room in the beginning of the game. Or maybe Jill and bella had a relationship that the husband found out about (Or jill is related to the husband)..
too many options.. lol