@Naja **********
Yes, technically. However, I doubt you would face a problem from immigration on this point. You might have a problem with the labor department for not having a work permit, though. But as Immigration seems to like this program (and why wouldn't they as it makes their jobs easier and costs them nothing) I think you could probably sleep well at night knowing you are very unlikely to get into any trouble with either immigration or the labor department as a Phuket Immigration Volunteer.
Back in the States, I noticed that police officers, and even former prosecutors never seemed to actually get speeding tickets. 😉 There's a lot of discretion shown in these sorts of circumstances. To be fair it's kind of a big deal for police officers to get traffic tickets as it can be considered a black mark against them by their department as it can be considered disregard for obeying the law.