Mileage discrepancy at my first BMW service?

BMW carried out my first service last week and when I checked the service book, I noticed the mileage recorded was about 400 miles less than the odometer reading. When I asked why, I was told they do a key/fob check for mileage and had I used the spare key for their use. What difference does this make and are they trying to pull the wool over my eyes as a woman motorist? Why don't they take the odometer reading and are there any legal implications here? My car is supplied by Motability.
BMW keys contain chips that record information. Dealers prefer to go by that rather than the odometer. 400 miles is neither here nor there. 4,000 miles would be.
Answered by Honest John on

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