My dad had a guy working for him loading firewood on a trailer in the woods. The guy gets in the truck and tries to move the truck and trailer loaded down with 2 cords of wood in 5th gear. When I got there, the transmission was stuck in 5th gear. (long story) But I started the truck and let completely out on the clutch and it didn't even kill the motor. We're talking about completely shot.
I unhooked the trailer, freed the transmission up and moved it very carefully in 1st gear out of the woods and on to level ground. I drove it around gently and the clutch started to come back to life.
I still haven't changed this clutch and we've pulled over 20,000 lbs with it and it doesn't slip an ounce. The truck is barely over stock power, maybe 240-250 hp.
I still can't explain how that happened, but it sure shocked me (and still is).
-Chris