I support an antag ban here. I've only seen Swat antag once as far as I know, but the way he did it was extremely powergamey.
I was playing Janet, and Swat was in the round as Fortune. She had an objective to kill Janet, and there was some attempt at some sort of RP, asking Janet how long she'd been married, etc. But then out of nowhere she runs into genetics in a full security hardsuit and a couple of laser rifles she made in R&D. A couple of officers were already there in the medbay, and ran over, while Skull, who was Erec, pulled Janet out and ran. A shootout between the officers and Fortune ensued, where I'm pretty sure that at least one was killed and several more injured. Janet and Erec went to the outpost with one security officer who'd escaped and Jennifer, being played by Gamegod. While we were there at the outpost, Swat immediately tried shoot-on-sight tactics, and critically injured the security officer, and moderately injured everyone else. Then Fortune got stungloved and beaten to death by Erec and Jennifer.