This situation is due to how Print Inspector alerts are implemented internally. The monitoring service is constantly receiving updates about what's being printed, and as soon as the condition is met, an e-mail is created and sent, while printing of that job continues.
For example, Print Inspector receives something like this:
- 1 page printed
- 5 pages printed
- 20 pages printed <- at this point the condition is met and an e-mail is sent
- 30 pages printed
- 40 pages printed
The printing continues and Print Inspector doesn't really know when the last page is printed, so the notification is sent as soon as the condition is met. The notification shows how many pages were printed at the time the e-mail was sent. There could be more. We agree that in some situations this may be confusing, so we will remove the count in future updates, as you suggested.