Or to put it another way, 300 CPM (which is a rate) is less than how much radiation you get when on a flight, or how much radiation you get at higher elevations. Even giving a simple explanation of how to calculate Greys (the actual measure you are looking for) takes up the better part of a page. Hell, your bones are radioactive. Yet there are plenty of people posting that somehow the risk to this guy is radioactivity. In reality, his biggest problem is probably going to be finding a new job.
For his job, depends on the dose he took. In my country he would have been on benefits until the dose was calculated, then if possible, reintegrated in the team, or directed towards a new job if not (paid formation and everything). I've studied with a diver who couldn't work with radioactive trash anymore, he wasn't meant to be a SWE in the end, he now dive for unexploded WW2 stuff in the north sea/Baltic I think