Please help me to understand the bold section of the following paragraph:

Log out user after (minutes): The time in minutes after which inactive users are logged out. Note: A user is considered inactive only if he/she has closed his/her browser or navigated away from the efront page. This is also the maximum fault for user time reports: In case a user navigates away from the LMS, his/her online LMS time may be reported up to X minutes more than the actual, where X is the value for this setting.

Suppose this value is X (minutes). Statistics showing the length of time users spend at the site may be incorrect (exaggerated) by up to X minutes. For example, if X is 5, and the user stays at the site for 20 minutes, then the reported time may be up to 25 minutes. This discrepancy presumably happens because the user is not actually logged off until 5 minutes of inactivity have elapsed, and the system counts all of that time towards the usage time, even though the user may not have been actually looking at the site for any of it (may have navigated away).

“fault” is a slightly unusual choice of word here. “error” would be more usual.