Well, we didn't scout, and we lost to two very screwed-up strategies. Note to self: Scout what they are doing before 6 Carriers walk into your base.
What our double-Protoss opponents did (and made my ally rage-quit 2v2s for awhile), was cannon every expansion, base, and pathway, and then proceed to go heavy air. I think they built absolutely no ground units all game.... and we lost. Shame on us.
Had we been able to counter, we would have expanded before them and Turreted everything - but of course the AI turrets are stupid and target fighters. I have no idea why.