Jumping off the oil rig, the first shot shows Doggett falling ahead of Mulder, the second shot the opposite is true, and in the last shot they are reversed yet again.
If there were a blowout on an oil rig, it wouldn't be a secret; and an autopsy would enable determining whether burns were caused by hydrocarbon combustion as opposed to radiation.
As a Marine, Agent Dogget would have known the proper way to jump off the oil rig because it's part of our swim qualifications. Feet crossed at ankles, weak hand holding nose, strong hand folded across it, holding the opposite shoulder. Jumping off the rig would have required the same technique as jumping off of an aircraft carrier because of its height.