Likely because the double hardpoints only occur to the defender's side that gets drafted in a coop mission.
I didn't see it in the convoy mission we were in together however, but since Tommy dropped at the beginning or the fact that it was a convoy mission, might have been the reason as well.
BTW, thanks for staying and fighting rather than just escorting the convoy off the map...Salute and a big kiss to my sporting Federation adversary.