^ not to mention that duce of hearts is exactly the card you would call out there. It's the most blank card in the deck and is probably the most often called out card when you need a blank river
Not really all that amazing as he obviously wanted a low red card. Its only natural to ask the poker gods to river the safest. Can anybody claim they'd ask the gods for a 5 of diamonds? You can be certain he was praying for anything non club.