I suppose it doesn’t matter if you stole this file or GF’s file or other files entirely (are you not also selling a version of this? Rhombicosidodecahedron files). None of it is OK. Rather than coming here and publicly trying to smear someone who is a well respected contributor to the community, I think you should right your wrongs, apologize where necessary, and move on. Just do better. And if you feel someone has wrongly accused you, reach out to them directly and work it out.
As for the FB group, perhaps you should ask the group admin why you were removed.