I was doing LFR and getting ready for bed so i was in and out of it. We killed council and i decided just to quickly leave after seeing i got yet another failbag. When i left the instance group and zoned into Towlong steppes my Bonus loot roll was up. So i though to myself "why not". I clicked roll but it gave me the error message "You cannot use that here". So i decided to spam click it and it went away as if i had rolled. I clicked exit game thinking nothing of it. Right when i exited i seen i had mail. So i logged back in to check the mail and the Bonus roll option was back on my screen. I spam clicked it again and the same thing happened. i went and checked my mail and it was from the postmaster. It had nothing in it. So i decided to put this to the test. I did the same thing on my pally left raid after killing a boss with the roll open. I went next to a mail box and spammed it. Opened the empty mail from the Post master. exited wow. logged back in. rolled. opened the mail. logged.....etc. I did it a total of 4 times. on my third attempt i got my shield(I did Primordious). So im assuming i got 3 losing rolls and 1 winning roll before the roll actually timed out. The best part is it didnt use any mogu runes of fate.
Steps:
1. Kill boss
2. With bonus roll window open, Leave raid.
3. Get next to mailbox.
4. Spam click roll
5. Open mail
6. Exit/relog
7. Rinse/Repeat