Visible crew/equipment: Just after Stackhouse is executed, Burnett runs up then down a hill. Once he's over the other side he falls and rolls down a steepish incline. In the background (top left of screen) you can see set vans lined up nicely along the side of a road. (00:32:07)
Visible crew/equipment: When Burnett cuts away from his parachute and falls to the ground from the tree, you can see the crash pad he lands on. (00:24:25)
Visible crew/equipment: When Burnett haves a sip from the Coke a boom mike is reflected in the bottle when he lowers it. (01:04:40)
Visible crew/equipment: When Burnett jumps and Glen catches him hanging in the air, Leslie shouts "Pull up. Pull up.", it cuts and the security wire attached to Burnett's right shoulder is visible. (00:32:40)
Visible crew/equipment: When Burnett is running through the mine field you can see a camera right in the shot. The camera takes up half the screen, but it can only be seen in slow-mo. (The use of slow motion is permitted when crew/equipment are visible.)
Visible crew/equipment: In several shots above Stackhouse and Burnett's plane you are able to see studio lights. (00:21:30)
Answer: The two seats collided in midair before their chutes opened and Stackhouse yelled, "ow!" Not realistic because in the 5 seconds it took for the second pilot to eject they would have been far apart.
But you see his leg get injured before his leaves the jet. I think the original question refers to how did that happen.
Ssiscool ★
The injury to Stackhouse's leg was from a pen attached to his knee pad. When watched in slow motion, you see it disintegrate and somehow throw shrapnel into his leg. It makes little sense, I believe it was merely a plot point to make Stackhouse unable to travel out of harm's way. This prompted Burnett to leave him unattended for the bad guys to find him as he went to higher ground to get better reception on the PRC-90.