They definitely weren't contractors. The posters only went to military and the pictures all came back from military email addresses.
Contractors live on military bases with APO addresses. I have been both. If they were wearing khaki pants...they were contractors (99.99%). They certainly were not non-tier 1 specops soldiers dressed like that (if they were...they probably wouldn't be posing for pics).
No personal weapons allowed at all. Accessories depend on the chain of command. Violating this is waaayyy worse than speeding ticket level.
edit: I notice now you said "email"..they could have been emailed from a soldier...or almost all contractors are former military, most very recent;y gotten out or still in the Reserve component. As a contractor I had a military ID, contractor ID, military email. All current, all active, and I was not unique.