Would We Have Found a Body if He Had Done That?

The woods of the pacific northwest are huge, and it's entirely possible for a body to go undiscovered all this time out in the wilderness. The fbi has a point, which is that cooper was not dressed for the weather he would find once he got to the ground. But on the other hand, dark rain, wind and cold would not have killed him in the five s before he reached the ground. What do you make of the fbi speculation that he did die? I'm not particularly impressed law enforcement likes to admit that someone got away with something so dangerous.