I get the feeling your enjoying playing devils advocate
, but I too would say it's a spar. I've had a few rescued spars when I was younger, one for around five years, and I picked an injured one up last year, which I gave to a friend. I see it on a weekly basis (that makes me sound like a divorced dad seeing the kids!) - she can't be released as she has a damaged wing. I've also seen hundreds of both spars and gosses owned by falconers over the years (I'm not a falconer BTW, never have been, though I was brought up surrounded by falconers, so to speak - sorry Spar!). As Michael and Spud suggest, it's legs are too thin for a gos, and I always think gosses, even males, have a squarer looking head than a spar, though I don't think this is mentioned in any bird book I've read, so maybe it's just me!
Michael's right about the Starling, very difficult bird to catch. I've seen spars give up on them many times because they were simply being outflown. When I was a child many falconers believed that hawks wouldn't eat starlings! Falconers can be strange people at times . . .
Pity we can't see the starling to get some comparison in size.
If you can, try downloading the pic and put it into Photoshop, then sharpen it as much as poss. using Unsharpen mask. The picture is far clearer.
Finally, I wonder why falconers call Sparrowhawks 'spars' and birders call them 'sprawks'? Spar is a far nicer name for such an athletic, noble bird IMO. please don't tell me the nickname for a gos is a gawk!!
saluki