Computer freeze at the game end banner!

So right at the end, My computer froze on the defeat banner for about 30 seconds. I used alt+tab so I know it wasn't just the game. There's no reason why I should be able to run the whole game but not the ending banner. Why is the end banner so laggy? Do you run it in 3D with some special algorithm? Do you run the log of the whole game in the background?