I killed Fabius Bile and part of my loot was an Uther's Tarrot card.  When I left the mission, I had all of my other loot, but the Uther's Tarrot card was zero.

This is repeatable.   Here are the steps:

1.  Check your count of Uther's Tarrot cards at the beginning of the mission.

2.  Kill Bile.

3.  Get Uther's Tarrot Card in the Bile loot

4.  Check your count of Uther's Tarrot cards.  It will have added by the amount of tarrot cards received (sometimes you get more than 1).

5.  Quit the mission before reviving the Alpha Pariah.

6.  Check your count of Uther's Tarrot cards.  It will revert back to the number before the mission