He was in an off-side position and he stayed in an off-side position. It is not as if he came back from behind the defenders. It should not have been allowed. It is as simple as that. If I was the manager of the Czech Republic I would've been very disappointed.
You have the best 16 teams in Europe here and really they're the cream. If it hadn't been for a late winner from the Czech Republic last night no side would be on six points from two games.