What makes you think so? Master training alone certainly doesn't negate path of iron, at least not with the latest beta (and I'm halfways sure, this is true for 1.33 either). A char of mine completed master training && has Path of iron active. What does negate the the quest is the molag bal quest itself. If you started/finished the daedric quest (dunno if speaking to Amir is enough), you're out of luck. Is the Molag Bal quest in your quest log active?
If not, while I haven't checked the script, infamy may play a role. Either complete the pilgrimage or if you're impatient, use the console.