Afterall, it didn't affect him in any way, so I don't know why he was arguing.
Men feel valuable if they can help you to solve problems. If we put forth what we believe is a great solution and you reject it for one which is (in our view) less optimal, we're going to argue with you about it. Even though, to your point, it doesn't impact us either way. I catch myself doing this too. You handled it the right way, "I've decided, let it go". If he's weak he'll make a smarmy comment and then drop it. If he's strong, he'll accept that as the last word and move on.
Accuray
Married 18, Together 20, Now Divorced M: 48, W: 50, D: 18, S: 16, D: 12 Bomb Dropped (EA, D): 7/13/11 Start Reconcile: 8/15/11 Bomb Dropped (EA, D): 5/1/2014 (Divorced) In a New Relationship: 3/2015