At the very least, umpires have to have a safe exit provided by the host school from the playing field. I don't care how bad anyone thinks they are, this has to be provided to them at a minimum.
If during their exit from the field during this game, they were met by unruly or potentially hostile fans, then the host school is at fault, completely. I don't care what either of the umpires said or did, they should not be subjected to this kind of behaivor ever.