Visible crew/equipment: During the base jumping shot, you can see what appears to be a camera man in one of the windows of the incomplete building.
Visible crew/equipment: When Lara's two Greek partners are killed in the temple, electric lights can be seen reflected in her goggles. (00:08:40)
Answer: Very plausible. The suits exist - they are called glide suits or wingsuits and lots more info can be found with a quick Google search.
Guy