What do Stints have to do with why the bird isn't a Pectoral?
I'm also curious why you're saying it's not a pec, because it looks good for one to me. Yellow legs, chunky shape, and the photos aren't good enough to see the perfect line on the chest. In any case, I think STSA also have the same line. The shape rules out LESA, and the yellow legs narrows it down to Pec and STSA, which is basically out of range.
Side note: if I considered every rare possibility when birding, I'd never ID anything to species.