Freeleech is applied at the moment your client reports traffic to the tracker, not at the moment you click download. So if the freeleech timer runs out while you are still downloading (or just before your client sends its next update), everything reported after the timer ends counts as normal download. That is most likely what happened here with only 8 minutes left on the clock. Best practice: grab freeleech torrents early in the window, not in the last minutes. If your numbers still look wrong to you, open a ticket via Support and we will check your account.