Come on, we're talking about Syphilis, not HIV.
What could be done is that the other performer he infected could charge him and ask him compensation 'cause they aren't be able to work (and get paid) before they are cured.
Anybody doing anything as remotely stupid as doctoring a test to make it look negative so one can keep working in the industry needs to be blacklisted from it for life. That's the minimum that the industry should do.
As far as intentionally exposing sexual partners, while working in the adult industry or in any other situation, to a serious sexually transmitted disease without their knowledge, yes I feel people should go to prison for that, even if the illness is treatable.