Another useful tip: because the conversion rate of 1.609 miles to kilometers is so close to the golden ratio (1.618), you can use the Fibonacci sequence to estimate a conversion.
1, 1, 2, 3, 5, 8, 13, ...
5 miles is about 8km, 8 miles is about 13km, etc
My first thought was that, because they're being investigated for training on data they didn't have consent for, they reverted to a perfectly legal version. Essentially "getting rid of the evidence". But I think something like your second bullet point is more likely.