Although the two teams were very close, I understand the feeling, especially if the opponent wasn't active and didn't show up at the game. I believe that the assistant's comment says it all. That they were really impressive is good, but to lose like that can be frustrating.
Out of curiosity, what were the instructions for your team? I ask because 4-5-1V style is typically a good formation for countering diamond, especially with the DMC blocking the opponent's AMC.