It is really important that the ECU update process not be interrupted.
I'm in Texas this week making timezones a bit of a challenge, but evolve is across this issue an will work with Marco on it.
With regard to the other 1M that had the issue, a phone call came thru while the ECU was being written to. Bluetooth was on so the call connected thru the car and killed the ECU update process midway. Once the ignition was turned on properly, the ECU did eventually respond and the file was rewritten. That 1M was back on the road with the evolve tune with no reported issues even after a couple months.
At the risk of stating the obvious, It doesn't matter what the ECU is being updated for (software update, tune etc) any interruptions to the process can cause issues. That's why BMW tend to keep the cars overnight when they update ECU software.
I don't know the details as yet of the issue that occurred with Marco's car, but it is being looked at and he is getting support.