Transmission fault mode

Took my 750LI 2006 to the dealership concerned about a "kick" in the transmission while shifting. They recommended a software update. Wehn done I took it for a drive with the tech and within our first few minutes , I noticed that the kick has gotten rougher. Soon after the warning light came on indicating a fault in the transmission and put it in a safe mode. Took it back in and after running a scan, they said it needed a new transmission. I left the dealership very frustrated, went home and came back the next morning to pick it up with an intention to sell it as is, due to the disappointment. I asked them to clear the fault code, and drove off with the car after I paid what I owed. Surprisingly the car has been running normal for the last three hours which compelled me to consult other technicians. Some beleive it could be a sensor problem missreading data which caused it to go in safe mode. If tran was bad how would it run normal afterwards?? Any suggestions?? I could not beleive than were going to make spend about 10K for something that wouldn't have been necessary. It still kicks but still running. Any suggestion???

find another dealership to diagnose the problem - sounds like the techs there weren't at the "top of their class".
Transmissions (or anything else for that matter) do not "fix" themselves - definately something faulty or maybe a loose connector.