The guy doing the sign language is at fault.
He should have introduced himself to that 53 y/o Rapper
before the performance. Not everybody wants this activity going on during their performance. Some may be concerned the signer may pull attention away from the main act.
It’s not exactly the safest occupation. There have many rappers attacked and killed recently. I understand the concern of having someone you don’t know near you on stage. Once clear, he did apologize and make good. I’ll give him that.