[Plugin: Jetpack by WordPress.com] Difference between dashboard stats and CSV-loaded stats?

There seems to be a difference between stats in the dashboard, and custom retrieved stats. Especially on fairly new posts, it seems that retrieving statistices can get a bit off.

If I look in the dashboard the stats seem more accurate, and new posts appear fairly soon in the list of all posts.
Then when I try to use this data in the website, using the stats_get_csv function, other data is presented.

Further investigation leads to the conclusion that data in the dashboard is loaded via https://dashboard.wordpress.com/wp-admin/index.php?etc.
Data received via the stats_get_csv-function loads data through https://stats.wordpress.com/csv.php?etc….

This leads to differences between post-counts my vistors see (less), and data shown in the dashboard (more accurate?).

Are my assumptions correct, and if so, how can this difference be explained (to my customer)?

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