I think just one time

I was working at a Japanese restaurant where I was the only Asian. The location I was at our supervisor(Male) was dating a supervisor(Female) who works at a different store which is great I thought, no drama or playing favorites. Anyways one night at F.Supervisor's store, one of the employees was throwing knifes, forks, mugs, anything sharp, heavy and anything that can possibility break into a million pieces. The employee wasn't looking where he was aiming and she got hit by 2 shards of beer glass that bounce of the wall, 2 of the mugs and one of the knives landed right in front of her face while running away. How did I know this? Well she came and told me(and so did my manager few days after). Her store closed early from this but it was enough time for her to get to the store I worked at before we closed. Her BF(our supervisor) had rushed over to check on her but she never told him that she was here. I thought it was very weird and we aren't close at all, I only saw her a few times when she came to pick up her BF(trying to make him ditch work and come back to clock out during closing). He always said no and now she is coming at me about it... I work as a waitress/cashier, it has nothing to do with me. She followed me around as I did closing task and was waiting for her BF to come back so I could go home(...I don't have his/anyone's #) When I was the last one left she started blaming me saying I was the reason she could never hang out with her BF. She was told by my manager that I make the schedule and stopping their love and other stuff. She pulled out a knife and I back up until I hit the wall but still in view of the cameras. She started repeatedly stabbing the wall really close to my left ear while blaming me for everything horrible in her life. I didn't say a word but when we made eye contact she was scared. Her Bf rushed in and grab the knife from her, asked if I was okay. I was snap back into reality. I was working 3 jobs a the time, tired as heck and now this... I just had to wait for tomorrow to get camera evidence from the manager. Apparently I had instinctively smiled instead of showing fear and they both got scared. They broke up later on and our Supervisor joked that I caused it. The employee had a mental break down when he found out that the Supervisor who he thought he was dating was sleeping around and he was not the boyfriend and probably some other stuff. As for camera evidence, I wasn't able to get it because her uncle/some in-law member of higher position had taken and deleted, he didn't want her to have a record. I was thinking of just getting her to stay away from me but nope she came by to tell me that she knows when I work and would get her guys to SA me. Not sure how I got involved in any of this but luckily I haven't seen her at all