same ol Steve

I am using a GT2871r on my single cam. Last night I took it to the track for the first time. I made several passes everything was cool,except my lack of seat time,on the 4th pass midway thru 3rd gear the car fell on its face,kind of like instant stock all motor.
I coasted thru the pass and idled back to the pits,popped the hood started looking for a loose coupler and all all the usual suspects. I finally noticed the threaded rod coming from the wastegate actuator to the ''clevis" that attaches to the flapper arm had come off.
I pulled the clevis from the arm and tried to thread it back on and discovered the threads on the inside of clevis had pulled out. They were gone about a third to halfway up the body of the clevis,I'm guessing thats the distance the rod was inside the clevis.
Two questions for you guys.
1 What would cause this to happen ?
2 Whats a fix to keep this from happening again ? Going to external W/G is not an option.