Ultegra FC-R8000 Chainring Bolt Fatigue As per my troubleshooting to find a bike creak (Ultegra FC-R8000 Right Crank Arm Creak) - I have installed and removed the same chainring bolts ~8 times. In the process I snapped one of them. Each of my installs have used a torque wrench at 14Nm with a Torx T30 bit.

I have noticed that when installed on a crank it seems more difficult to push the T30 into the bolt, but when they are removed it is easy to slide the bit into the bolts.

Has anyone else experienced this behaviour from these (or other Shimano) chainring bolts? Am I doing something wrong if this is happening?
For what it's worth - the best answer I've been able to come up with/figure out is that when I was torquing the bolts down I might have been putting force on both the crank arm and the torque wrench and maybe doubling up on the force...