How would you have executed the jump? Better yet: if someone came to you with the following conditions then how would you reccomend they execute a jump?
Night, freezing cold, rain, wind, drop zone is in mountainous and forested area, speed is over 200 miles per hour, plane is not a typical skydiving plane, you're carrying 200,000 dollars however much that weighs.
Do you wear a helmet, gloves, goggles? Altimeter? Boots? Flashlight? Jumpsuit?
If DB Cooper was a skydiver then he did a great job of fooling everyone. The FBI says he was not experienced. I read that somewhere but can't remember where.