Rambotnic's rating looks weird to me. One negative and one positive, so the total should be zero I think. Yet it's showing as -1. Is it because of my own neutral?
-1 is the correct number. He gets -2 for his single negative feedback, and +1 for his single positive feedback. You can follow the calculation from theymos' code:
You're right. The counter-rating only works if there were prior positives (or he needs two counters).