The Pentagon refused to bomb the convoy because the vehicles belonged to civilians and they were probably transporting the wives and children of some jihadists.
Comment: A fine sounding excuse, but unlikely. Since when have humanitarian concerns hampered the U.S. war machine?!
However, the Iraqi army decided to bomb it, destroying more than 200 vehicles and killing their occupants.
Iraqi soldiers are convinced that the Pentagon had received instruction to let the CIA advisers, that were training the jihadists, escape.
SOP.... always allow time for an exit of personnel that matter... the pawns don't count.... totally expendable and replaceable... so far.