ajohn

I don't think there's much evidence of hybridisatioin - the white on the right flank is perhaps not quite as extensive as usual but it's hard to see what other species would cause this. The white in the wings looks fairly normal (ie extensive white on the primaries and secondaries).

Given the state of the plumage, especially the apparently clipped left wing, I think it's very unlikely that this is a wild bird

But at least we can be sure it's not a scoter ;)