Actually I disagree. David brought Hulk to a lake so he could take him on in a form that Hulk's brute force couldn't really harm him. No matter the force, you can't beat up water. Nor can Hulk move with the power he does on land. David was very intelligent, so you have to see this as part of his cunning. He got to do what he wanted(absorb Hulk's power) and so doing destroyed himself.
If David had of fought in the desert, Hulk would of smash his father around. Hence him bringing Hulk to a remote place(no military nearby) where all that strength is handicapped. Giving David the upperhand. And it did work, it failed because he underestimated just how strong Bruce/Hulk were. Far and away from his own overconfident potential. It fit perfectly. Doubly so because its usually true, abusive parents are oblivious to how damaging what they've done is to their kids.
Go plug the dvd in, and skip ahead to the scene with Hulk in downtown San Francisco. The fake cliche ending. First thing we see when it cuts away is David, and Ang uses 2 panels so he can show David leaving the cell, but the top frame is frozen on David's eyes, those cold cunning eyes. And it slowly fades away. This was planned for all along. The only thing in the fight that goes wrong for most people is the huge Jellyfish form David took to help contain that power. If that wasn't shown, the scene would be more digestible for people. I think..