I am currently running a mage build, and I'm running a DoT build with tear of etheliel (among other's). I have noticed that immoral offering never procs when the freeze ailment is applied (at least from tear of etheliel) and an enemy is killed. I suspect this is a bug, unless freeze ailments generally do not proc immoral offering. Might be worth looking at, or correct me if I don't understand the skill correctly.