Hi Tony
I'm glad the 410darc is performing well for you
We have not heard of any driveshaft popping issues and as you say the rear shaft is in by a lot on the V3 longer rear outdrive.
The only thing I can think of is, was the shaft in when you started the race?
I have seen a few durango owners in eagerness missing a shaft when fitting the clutch.
But other than that I cannot see another cause
Very odd that one
Thanks