Camshaft regulator failure - advise needed

[powershift]

I don't think the vehicle would have made it 40K miles, if there was an installation issue with the cam drivetrain.

Hypothetically, if the bolts were re-used and already stretched then there could be the over-torque condition and strain the metal at the end of the cam weakening it. If the cams were broken inside the head and somehow wedged, then I could see how the snap occurred, but that wasn't part of the story.