Everyone else has pretty much covered the topic so I'm just going to throw in an answer to the topic title. Should models have their mental health tracked before camming?
Well, if you want to remove almost all sex workers from the face of the world. Then yeah, I guess we could stop people with mental health issues engaging in sex work. Mental health issues are common in all lines of work, but I'd wager that the sex industry is where they're particularly prevalent. I'm not entirely sure what this mental health examination would be monitoring, because it could be depression, history of trauma, eating disorders, addiction, OCD, schizophrenia, autism.... I mean, the list is pretty long and completely range in whether they'd affect your decision making. Actually, people with issues in decision making might pass all mental health tests with flying colours. And say something like depression could be quite severe, but the person might not be a suicide risk. While someone with mild depression or even no depression as all could be. Where is this line being drawn?
So yeah, basically if we start screening for mental health issues, we'll probably lose a large portion of our favourite sex workers. As has been mentioned, sex work, camming in particular can be a great alternative to those with mental and physical illnesses who struggle in regular jobs. There is also that abuse victims are often more drawn to sex work, largely because it's got a safety and familiarity to it as well as being risky, something which comes hand in hand with mental health issues. I don't like saying it because people who are anti-sex work often use it to harm the trade without really understanding the workers choices. But, it does seem to be linked so I guess it's just important for sex consumers to act responsibly and be considerate (shock horror).
In terms of whether you can prosecute the member. Well it's pretty common sense. If one person, whether model or member, was knowingly pressuring the other person to engage in risky actions for their own gratification, then yes, they should be liable to some extent. Sadly with choking, you can kill someone quite easily and the person being choked wouldn't necessarily realise as they'd pass out. So I can see how this could happen. Sounds like the guy was aware to at least some extent what was going on and was pushing her to cross those lines. My guess is that she trusted him and felt gradually pressured into doing more. Maybe she enjoyed the thrill of it or just wanted to please a good customer. He maybe seemed more experienced and persuaded her she wasn't in danger. It does happen. Predators know how to get under people's skin and there are unfortunately plenty of people into BDSM who will use their dominance to persuade their sub that they're safe and to push boundaries when engaging in risky actions.