occasionally I play a "perfect" game and my ACL is as high as 20 and this game isn't "perfect" and the ACL is 1 :(
Your game went on for a very long time and you were in a strong position to win right from the start. If you then make a move that is not very good, but still keep the clear advantage, you don't lose CPL points.
I always made very good moves in my "perfect" games
Otherwise it wouldn't be a perfect game ;-) xD