I find it highly informative that the required PPE for working in that location is a life jacket so you float in case you fall in, rather than a tether and fall arrest harness so that it's not possible to fall in.
300 CPM is nothing, background levels might be 150.
Background is probably a bit lower depending on where you're at. My counter went through airport security luggage scans 'cause they wouldn't let me wear it through the metal detector. It beeps for a few seconds and then comes out about a days' dose of natural radiation higher. The count was higher than 300 CPM, but obviously only shortly.
That poor bloke might stay at 300 (if ingested and he can't scrub it off) for a while but it's still not very discouraging long-term. Pilots have about that at cruising altitude.
He went back to work the next day. They don't provide much detail about the minor injuries but it seems that the biggest issue is maybe a bruised shin from the fall.
