So here's the update.
Got the vehicle back, seems to be running okay.
The faults codes indicated that cylinders 4 and 5 had misfires, with fuel injection being deactiviated for each.
The fix was to replace four of the injectors with updated BMW injectors. It was noted that they had seen this a couple of times with newer model X5's and changing injectors seemed to fix it. They noted that they were going to only change two, but moved the misfiring ones to other cylinders to test, so they decided to change four of them, once they took two others out.
Any one else have this issue?
Any one care to comment on how serious this is or if there may be a potential for it to happen again? (I'm not a mechanic so I really don't know)