It was more likely caused by engine torque. A bolt could have been loose, allowing the diff to move. If it was loose, the diff would try to rotate backwards when the machine moves forward. That would put a lot of stress on the front bolt.
I ripped the front diff completely out of the frame on my Grizzly 660. I had filed the mounting holes to move the diff closer to the drive shaft. It ripped the holes right out of the frame mounting tabs.