As many of you already know Costa Rica's FA is filing a complaint with FIFA over the fact that their game (which the lost 1-0) vs the US wasn't postponed due to the weather. I was wondering since Costa Rica willingly took the pitch and played the full 90 without complaint, how can they protest it? 

The coach should have stopped his players from playing, the 90 minutes are up and you can't get a replay. There was a lot of snow and the ref should have asked the coaches if they wanted to play or postpone. Nothing they can do now.

If the ref deems it safe to play, you play, and if the full 90 mins are up then you can't do anything about it.

In fact, the ref did confer with the coaches and the players on both sides, and the Costa Ricans were all for going ahead. Was a ridiculous game, but couldn't have played the next day either because of 12 more hours of predicted blizzard.

*Update*: FIFA is looking into Costa Rica's complaint and will rule on it in the next week. Go figure.