Okay, so I just returned to wow today, I've messed about a bit on my mage (Link in sig). I have pretty much the best gear available, I crit geared people for a maximum of 55-60k maybe, with procs etc. This Oxina's gear is inferior to mine, so there is but one conclusion: Altered circumstances. He was most likely under the effects of a power up, or you were under the effects of Recklessness. Regardless, fire is ridiculously OP atm, I go through people like a hot knife through butter atm, after having been inactive for almost 3 months. It's just like any other X.0 patch prior to the release of the next expansion, the numbers are so off balance-wise because they ARE tuned for level 90, NOT 85.
Edit. Just transferred today, the character will be updated some time later I guess