Something with computers on the assembly line probably got mixed up. But the real issue was that nobody at Dingolfing caught it before they put in the box and sent it to SO CAL. They have like special checking processes they have to go through before sending the car off.

All in all the issue is resolved. BMW sent the M6 running board and the car was fixed in a matter of a day and delivered to the customer so in reality its not really a big deal.