I think you must have served in a different Iraq to the one I went to. The IPS were useless, devious and their loyalties definitely lay elsewhere. There were exceptions, but we had loads of instances of IPS vehicles being used as the dicking screen before & after attacks, as this seems to suggest.
They had this sort of Gucci thing going where they took the stocks off of the AKs- they thought it made them look cool (along with their huuauge berets) It also made them incapable of hitting a barn door at 10 paces. Not a bad thing really. As far as the ND/ random firing goes, it would have been a lot safer for everyone concerned if we had issued them with blanks.
My experience of the Iraqi police was bad. We clocked an IPS vehicle dicking us and stopped it. They claimed to know nothing and we had to let them go. 10 minutes later our vehicle was hit by an IED.
We were involved in several more incidents, including one where we were forced to dry fire and manouvere out of an IPS station and another when we were met by IPS double manning the sangers, PKMs pointing at us from the roof and the IPS commander cocking his AK and pointing it directly at several of us.