Seems The Craft is a legit combat training & security services group started by lauded sniper Chris Kyle: http://www.thecraft.com/
Makes sense for them to use such an event as a training scenario. Mingle the crowd, practice coordination, look for threats (not expecting any), look up a lot (being a group born of snipers), ready to help when S did HTF.
Fast looking mundane and innocent to me.
Innocent to me, too. Craft is populated with ‘the good guys’. There are several NGs wearing the same ‘uniform’ but they have their guard tag on their backs/packs.