I think that is a problem with most Judo classes Leo, the lines between light Randori and full on randori get blurred very easily.
Regarding someone in your Judo class getting busted up every week, welcome to Judo!!! That is a pretty common occurence in every class I've been to.
Along with boxing, no martial art (and I include MMA in this) takes more out of a person than Judo IMO (although Wrestling looks nearly as bad, I haven't wrestled).
The way I see it, you have some options:
i) Look for people who go light in Randori, and only ever spar with them.
ii) Do limited randori. Maybe only do one or two sessions, then sit the rest out.
iii) I know you might not want to hop out of Judo so soon, but consider BJJ. As I said before, BJJ is about 10 times safer than Judo. A guy on sherdog said he met a Brazilian BJJ instructor who also did a bit of Judo. The guy from Sherdog also did a bit of Judo. The Brazilian coach explained BJJ thusly "BJJ is like Judo except you don't get injured all the time!" If you want to keep doing Judo, maybe cut down to one class a week, and do BJJ instead of your other Judo classes. Or just drop Judo altogether.
I realise I may get a certain amount of flak for suggesting opting out of Judo so soon, but you have to take care of your health first and foremost Leo. If you aren't trying to get to the Olympics or don't have a burning desire to do Judo and the randori situation doesn't improve, it may be better to try BJJ for a while.
"Let your food be your medicine, and your medicine be your food"