Critting your opponent.Follow

I don't have much gear in the way DPS, but I've picked up mostly level 80s pieces from heroics that I use, with gems and AP enchants. Most of my gear falls in the tanking category. I've read just about every sticky I could on PvP and critting people. But I haven't found weather or not your defense in heroics being 540, does that make it so players can't crit you as well?

On another note, have you ever had just a vicious string of crits on someone in a BG, and for the rest of that BG this person just avoids you all together?
I had just gotten finished with an Orc hunter, he got me down to 75% lol. Anyhow Along comes this Troll warrior. He charges me, I'm stunned. But I still had about 80 RP left from my last fight. I get my diseases up on him as quick as I could, Runestrike is available so I hit it. And Would you know it, it crits for like 6700. (Which is alot for my gear) Then I follow it with an OB for 5400, then a FS for 3670. After the last crit, he Intimidating Shouts, and runs away. Just thought I would ask.

Edit:
I forgot to mention. I hate spending 50g to respec between BGs and raiding. Is it really needed or is it just a personal preference? I'm a freshman in HS this year. But I'm still a penny pincher. And in this case its a gold pincher I guess. Any input on what I can do to maximize my play in game would be appreciated. And please forgive the wall of text.

Edited, Mar 2nd 2009 6:10pm by Carmeliens