ECU cloning?

[MaverichX5E70]

Hey guys, so I'm a fairly new 2011 X5 35d owner and when I was first looking at the vehicle it had a CEL. The dealer I was purchasing from (Non-BMW) dealer said he'd get it taken care of so he made an appointment to have it checked out at our local BMW dealer.

BMW determined it needed a nox sensor. Sensor was replaced and now when the BMW tech is attempting to run the vehicle through it's tests, the vehicle stalls.

The dealer I bought the vehicle from has been good. He's picking up the tab for the nox sensor but he's pissed with BMW because he feels it's likely the bmw tech working on the car did something and fried the ecu.

BMW SA says the ECU has to come from Germany, takes 10 days to get to Canada and costs several thousand dollars.

I know the dealer I bought the X5 from doesn't have a huge margin and has been very good, even offering to let me drive my trade in with a dealer plate until everything is resolved.

When I was researching E70 X5 35ds I contacted Malone tuning for an alphabet delete and tune, and at the time they recommended a spare ecu in case of any necessary tune updates, etc.

Does anyone know if it's possible to clone an ECU? I'm guessing since it was recommended I had a spare, I'm assuming when they suggested that they didn't mean to spend $3K on a spare.. so.. My question is, has anyone had their ECU cloned, and has everything worked ok after?

Thanks for any help or suggestions