That's what used to happen.
I for one liked it back when if the guy quit and you were up by 21 on the CPU, you could make the CPU concede defeat.
but, the same thing happens if your up and you count the game after someone quits in the 2nd half.
the only thing that was annoying is that if he quit in the first half, you had to play out the entire game.
back in Madden 06 for the xbox, I could just play the CPU for the entire second quarter, then when the half came grant mercy and move on. That's why I had an 81-11 record, because I didn't have to mess around with the cpu, I could just get my win, which encouraged me to finish out what little game I had left.