As of now the runners know what mission they are going on, they know its dangerous. But they dont know about the rigger joining the team. My origanal idea was to have the director/producer run the cameras and whatnot. But that would be too much for one guy. Also the director recently came in close contact with what runners deal with on the reg, and has had second thoughts about being on the front. So he and his assistant will remain at the base camp, aka, the vans.
About the rigger, i assume that the director was able to find, through his connections in the film biz, a reliable and resourcefull person. The rigger would know before hand what kind of job he is signing up for, and would have gear to match. As GM i admit thats its not easy to resist just giving him what i think he needs, as oppossed to what he actually would be able to get in the story.