Boyfriend told his ex girlfriend he was gonna punch her in the face

My boyfriend and I have been together for a year now and he has a psychotic ex. Like she probably needs to be locked up psychotic. She needs to stop dating and hurting people psychotic. Her own mother has apologized to my boyfriend on her daughter's behalf psychotic. I have seen all the evidence of how she treated him in that relationship but also everyone in my boyfriends home town who's either dated her or been friends with her has a horror story about her. My boyfriend has a lot of trauma from that relationship. Especially since she couldn't let him go and stalked him for two years but then also helped his abusive step brother who did awful things to my boyfriend stalk him for a year and is the reason he had a mental break down and ended up going impatient. My boyfriend for the most part is very level headed and has done a lot better healing from things. Plus he hasn't heard from her in months and figured she finally left him alone. We went to October fest and he was kind of sad because his best friend had been gone for 4 years that day and they always went to October fest together. He got very drunk. I tried to help him back to the car. We ran into a mutual friend who told him his ex was hear and asking if he was because she wants to talk. My boyfriend said he obviously doesn't want to talk to her. The mutual friend said he understands. Just relaying a message. My boyfriend sits down to throw up. Pulls out his phone, goes to face to unblock his ex and sends a voice message saying "Leave alone. You psycho bitch! If you come up to me after I've told you for years to leave alone, you're gonna get your fucking teeth knocked out." I did not like that. I understand he was drunk and emotional but I want to tell him that maybe while he's grieving no more drinking. He wanted to go to all days of October fest but I don't think it's good for him while he's grieving