The wing-length is clearly wrong for Baird's Sandpiper. Unless by some fluke it has managed to lose the outermost primaries on both wings. It just doesn't look like Baird's on shape. I would agree with Graham Etherington that a dark-legged Temminck's or possibly a short-billed Dunlin. Small, short-billed Dunlin really do look like stints at times.
Then again, I haven't seen the bird so my words don't count for as much as those of people that have seen it...
Taking what one of the observers said. "The tail was brown and the rump edges white, with a black band running between." Then Temminck's should be a non-starter as you really shouldn't miss the white tail-sides of a Temminck's in flight. I would suggest it was a male arctica Dunlin (shortest, straightest billed of all the Dunlin sub-species). The tail projection does appear to be at its greatest when the bird's head is down and so the wings could have been pulled forward exposing more of the tail than when the bird is in a resting posture with its head up.
Once again we are dealing with extremely grainy record shots to make assumptions here but if you are to ignore the field descriptions, then this bird in my opinion is a winter-plumaged DUNLIN. I cannot see any Baird's Sandpiper in it.
However, knowing the calibre of some of the observers, I cannot see how they could possibly have made that sort of mistake and can only assume that the images are nothing like representative of the bird's actual appearance
Just been dissecting more of these images and really cannot see anything other than DUNLIN in them - it just goes to show how deceptive images can be if this bird was an adult Baird's Sandpiper in the flesh !!
The video stills in the initial link are extremely poor and I would not think it possible to make an I.D. on the basis of those.
Do you not think that the bill is very short for Dunlin? In the last frame I believe it appears longer because of apparent elongation by some background "crud" which just appears as a continuation of the bill.
I have never seen a Dunlin with a bill this short, and would myself be in the "stint" camp.