Is it a snowball?

I was at home yesterday morning when I heard a thump against one of the windows. I thought someone had thrown a snowball against a window at first. It took about 5 minutes before I found this guy on his back still breathing. I turned him over but he got a bit wild. So I couldn't pick him up :) But after 10 minutes he/ she managed to fly off again. Anyone know what it is?

My colleague Michiel says it's a black tailed godwit which we call a grutto in dutch. The crazy thing is what is he doing here? We have lots of these birds here in the summer. But this bird should be in South Spain/ North Africa with his mates during the winter! Anyway he's gone now. I hope he survives the winter here. He looks a bit weird because he had a feather in his beak/ bill and his tail was folded over after landing on his back. When he flew off again everything was back in the right place.