Since they were currently waiting, Leonard Ethan didn't plan on using these cards yet and decided to wait until everyone got back to the hotel to use them.
Realizing that the clean-up work on the workbench would continue for some time, Leonard started thinking about the benefits he could gain from this trip, aside from the cards.
Most of the jewelry found in his property had to be handed over, as they were part of the plundered wealth, and there was no room for negotiation.
However, the file guard ring didn't need to be handed over, as it was the only item in the pile of jewelry that wasn't considered looted, so it naturally belonged to Leonard Ethan.
Taking into account that the purpose of this trip to the Czech Republic was to obtain 10,000 Euros, this ring worth over 20,000 US dollars was also a significant gain for him.