In Isolation you get in the ghost and then you drive it towards the tunnel that shoots you under to the place where you got the ghost.

You then pick up the shotgun and get back in the ghost, then you drive down the tunnel with the ghost, the ghost will get jammed so you can get out and you won't fall down.

If you stay in the tunnel with the shotgun you will take everyone out as they come down.

This works better if your team protects you while you get everything.