Carfax mileage history

Looking at a truck and owners says 143k miles. On carfax I noticed it says 207501 on most recent update, however one month a few years prior the mileage jumped 44k miles in like 30 days. I'm assuming this is just an error along the way. When back calculating the error on carfax it does add up to the mileage he claims to have so I think all is ok. Is this a common thing seen on carfax?