Termination due to Retaliation

A coworker expressed to another coworker she was going to "beat my ass". Immediately after telling him this she sought me out, got up in my face and put her hands up as if she was going to choke me. I was concerned for my safety and brought the issue to my supervisor. The employee walked by my desk and said "I took my write-up." Shortly after, with my adrenaline still pumping from being threatened, I made an offshoot comment to the effect of (I can't recall exactly what I said) "They had better watch out because it's not hard to just get some barium. You can't trace it in an autopsy. I also said after that I'd never do that. Someone overheard me and told her. She then called HR and I was suspended without pay then phoned and terminated with no opportunity to defend myself. The company is aware she threatened me first and I have a witness who watched her get up in my face as if she was going to attack me. She was not suspended or terminated. Do I have a case here? I really hope so!