Yes, it would be double dipping. If you know that all the tuition costs were paid by his benefits, then you do not need to enter the 1098- at all because there will be nothing leftover to give you a credit. But since you've already started, If you do know all the Box 1 amount was paid by the VA, then just enter the box 1 amount as VA benefits received. If you are not sure how much of that amount was paid by the VA, then you would have to go back and add up all the monthly amounts deposited and enter that total.
