Land units didn't capture capital

Me and Leaf (we are allies) were trying to take my capital (Greece) back from orange. I sent 10 bombers and Leaf sent some stealth and 4 marines. After the battle, all orange units in my capital were eliminated but Leaf's marines didn't capture my capital and caused me to lose.

The picture doesn't really show clearly what happened, but it is the only SS that I managed to get :/