Just because he signs a message it doesn’t prove anything. I could do something bad, claim I was hacked & sign a message from an address owned by me, linked to this account since 2014. What does that prove?
Nothing at all but we are relying on what we are getting information here. His alt account just have claimed that he has been hacked. I was surprised to see this thread since I remember bitcoingirl.club had mistakenly public that you sent him a PM other day.
Anyway, I think there are more info to come soon and only bitcoingirl.club can say what happened.