Good player CC reads "opponents target number is 6", Shadow also played a CC reading "add 1 to combat roll". Is the SP target number still six? or does the target number become 5 or 6? I assume the later, but it is certainly not clear.
The target number is 6, but the Shadow player only needs to roll a 5 to hit in the Combat Roll, since he/she adds one to the die rolls. Think of it this way: you add your modifier to the number you roll, so a "add +1 to the Combat Roll" means a 5 becomes a 6.
"War is much more fun when you're winning!" - General Martok