He probably Ct'd for the purpose of trolling you, hes laughing right now.
I agree that it is unrealistic. To make a clarification, there is a 5th player 'lucky fan', so it isnt a complete 4 on 5.
The problem is that all these tools (enthusiasm, effort, HCA) are in general unrealistic, you can make an argument for the real life application of HCA, especially if your the denver nuggets. However enthusiasm and effort are built in for the sole purpose of making things like these possible. Sure some teams and players take it easy and take days off, however i dont think the general manager of a team goes to its players and says, "listen boys, take it light today, you might lose though".
What I'm trying to say is this, maybe the advantages are a bit over powered. But thats what makes this game, interesting, its what makes this game have an extra strategic value to it. a 4th seed can beat a 1st in the right situation.
You got unlucky, and out hustled, it happens.