What just happened?

During Escape Mode earlier, I entered just before the team switch. When I did get in, my wonderful bag 1(ak-47 silver, desert eagle camo, axe) was suddenly replaced with a strange bag. (m16, knife, grenade). When I accidentally shot my gun, I suddenly got a headshot double kill, even though there was no opponents even close to me. Knowing this to be bad, I instantly backed out of the game, but was prevented from leaving the room, so I had to exit the client. Could anybody explain to me what happened?