It's very possible to get loads of kills and hardly any deaths on Infantry Only Servers. This is usually because there are about 20 medics on each team......I played the other day and got 25 kills / 2 deaths.....not because I wasnt getting shot but more due to the fact that I kept getting revived by Medics. It only registers as a death if you arent revived before you re-spawn.
It's called having a good squad (any squad with medics that revive you), or, he just got revived alot, or he just barely died..
But 30+ kills per round is nothing unusually high, that's a little above average at best.