The fact that eight people were able to get along for so long actually amazes me. Likely, there was a misunderstanding and, worst care scenario, a conflict of interest.
Are you are not equipped to work with a toxic person? Is someone creating a toxic relationship causing you direct discomfort or an uncomfortable work environment? Is there an external factor that is not being considered?

Think about ways to ask this person, 'what is causing your distress?'. Seek an authority figure to work with. I feel that many larger corporations will seek the simplest solution to fix a problem and sometimes they settle with the most cost effective solution. Try not to feel bad, you made the right decision to leave as it sounds like what was enjoyable about the group became uncomfortable. Chances are there are others who feel the same way. I think it is nice that someone thought to ask why you left and maybe all she could think to do was get everything out into the open to avoid future conflict and clear a misunderstanding. I mean, when put on the spot like that it can be difficult to express your feelings and not attack someone else in the process.

Try to keep a clear goal of compromise or amendments for the future benefit of the group (without compromising too much of yourself or your beliefs). I hope my feedback in not too personal, but I get how a small misunderstanding can easily escalate into a larger problem. Take your time and don't feel pressure to mend your relationship. Put yourself first