A totalitarian government such as Iran's would not let these weapons out of their control. They must have gotten to Iraq through official Iranian channels.
It's one thing to engage in urban sniping where the engagement ranges seldom exceed 100 yds, quite another to shoot at targets up to a mile away. This weapon implies LONG range engagements against people & vehicles (helicopters & Humvees). It also implies that the snipers are going to have advanced communications & spotters. In short, the shooters will be Iranians, because the marginal increase in targetting would not be worth the training & support efforts for the Mookie Bunch.