I have a hard time believing you didn't know.
1. You were killed once, mening you had pvp on, and you turned it off.
2. If you tried to kill them with melee, it would have informed you you had pvp off
3. You seemed well aware that lava isn't covered by the pvp toggle function
4. I dont think you have to be unfamiliar with the rules to know if there's a function preventing you from doing something, it's against the rules to get around it, lava/bow glitches in non-pvp areas has been against the rules for as long as the server has been around
Please don't try to cover up your rule breaking with a shield of being "uninformed" and your own self-righteousness... You (may have been) harassed in chat and killed in the nether. This is a pvp server, always has been, get your revenge within the rules, not with gimmicks to make yourself invulnerable.