It seem to me as though the person you need here is "Flying Lawyer"
Do a search for his/her user name here on Pprune and refer him/her to this thread by either private message or email.
You may be asked more questions, but this is one person who really knows aviation law and procedures.
I wouldn't begin to offer advice as I wasn't at the scene. However, it is normal with the airline I work for that all the members of the group travelling together on one booking where some are being unruly would be offloaded. In addition to the fact that you are all considered accountable, there is the major inconvenience of having to offload some bags from the group, identify the ones of the people who are travelling and re-load them, causing a massive delay and inconveniencing everyone on board. Far easier just to offload the group and its baggage! Naturally, the airline would probably present this logical argument to the court as well.
Contact Flying Lawyer and see how the land lies!
