Guess what?

The blue player won four questions in a row, and he/she played the cards every time without any problems! This means the wrong sub didn't get set off all four times!

Tomorrow morning, I will do a test run with the blue player winning the first question, and the red player winning the second question, and the blue player winning the remaining two questions, etc., and see what results I get. It looks promising that there is significant progress now!