In a not-too-long ago patch, it was mentioned that because resilience reduced the chance to be crit, that on-crit abilites (enrage, etc) would proc anyway if resilience pushed the crit off the table.
However, I'm sure it was RPZ that mentioned that the coding involved to do that in the purest sense of the word would have caused server side issues (having to keep a new entry in the swing table to cater for a crit that didn't crit). As a result, on-crit abilites were changed to proc off non-crits at a rate proportionate to the amount of Reslience you had.
eg, if you had 5% resilience, you had a 5% chance to proc enrage off a non-crit.
RPZ .. was that you, or was it somebody else on this board.. I clearly remember it being mentioned, I just want to trace it back to where I heard it.