Why don't you read what the issue actually said?
Xavier: "Would...have lost--but I sensed Jean fighting her Phoenix self...helping me..."
So, Jean helped Xavier by fighting her Phoenix self. Nowhere did it state that she was boosting him. You are adding extra panels. Again, the issue defined HOW Jean was helping Xavier in that fight. Also, Claremont referred to it this way as well years ago on the boards when he was talking to some Jean fans.CC said that Dark Phoenix held back because of Jean's humanity which is how Xavier won this fight.