No, it's not user error. I've had it explode a multitude of times with control lock disengaged. Several times it was at the beginning of taxi, and at least twice it was while taxiing very slowly. And I mean VERY slowly. One time it was just as I was turning on the runway from a complete stop. Moved about a foot before the explosion, so didn't even have time to go fast. Most of the time I get that heavy breathing effect before the screen goes dark...and then: blammo.
As someone else suggested, I think it's hitting invisible bumps. But...it could also be a combination of hitting invisible bumps and a sync issue because it's only happened to me online, and so far only on the Syria and Marianas maps.
I don't have any tracks because it's only happened online and I don't record or save online missions. But, if you want to see for yourself, you can go into the TTI Syria server, select the MB339, start her up, and...see what happens.