I broke one of my boards last year. At the time it disturbed me greatly as everything seemed to happen without cause. It was my first run at ECES. Probably my 5th turn of the run, I hit a mogul and my intec heel dissintegrated and the board broke. There was very little there to indicate something like this should have happened.
As I reviewed everything, it occured to me that the last run I took on the same board at SES involved a collision and my foot coming out of my binding. I clipped back in a rode to the bottom of the hill without any problems.
If you examine the above scenario though, it was the very next run (2 weeks later) that everything went to he!!. Every crash that a board goes through, every turn that a rider makes is one turn or crash closer to failure.
Boards break, just like that fuel pump, transmission, shock absorber, etc. on your car. Something happens in their lifetime that results in failure the next or nearly next time it is used.
Boards break. So do people. Hopefully the board breaks first.