Ringed Plover or Not?

I spent over two hours last Monday at Poulnasherry Bay, in west Clare chasing down this plover, as it showed strong characteristics of Semipalmated Plover.  Can anyone shed some light on this bird for me. It appeared slighter than the other Ringed Plovers on the mudflats and the bill, lores and structure were very close in my opinion to SP Plover. I did not see any webs on the feet due to the fact that it walked for the majority of it's time feeding in wet little puddles. The set of shots below were the best I could manage on the day and birds were eventually dispersed by a hunting Peregrine. Why is this not a SemiP Plover? Please leave your comments. Thanks. Murf.

Plover Poulasherry John N Murphy