The Mechanic was finally able to get error codes. They kept driving it until the malfunction happened and immediately read codes. They said it was transmission electrodes and a valve of something.
The dealership also paid for a nice suv rental for the week. They also are going to start another 60 days warranty when the X5 is ready, mileage is unlimited. So I'm pleased with the dealership.
I realize that it is a used car and problems are to be expected to a point. I just thought the trany and it's components would have lasted a little longer than 65k mi.