Guns drawn and arrests made at gun show. Craziest gun show I have ever attended

I went to a gun show recently, as we were walking through the parking lot, I hear screaming, “get on the ground, and get on the ground now”. I pulled my camera out as fast as I could and got this video. I never got an answer of what happened. But from what I heard and was told by people around, the arrests were due to a possible “illegal” gun sale. But I cannot confirm that. At first, I thought the arresting officers were ATF. later, I did find out that the arresting officer were from the attorney generals office.