Yeah, I caught that, too. Actually, the upper left one has a blue ring (on the watch) and a distinctly yellow (instead of green) spare ring; heck, even the watch strap's pieces are yellow (as opposed to green). I'd guess that there must be an Alpha team watch set released, but it's definitely unclear as to whether more than one type of set was released. The brickset link shows the set contains Dash (and the regular features: blue ring and green ring). Brickipedia, brickset, etc. seem to show no information on this. I tried contacting LEGO about this, even though they discontinued the series they must have some information in archives or something, but no response from them yet.
Also, were sets exclusively released in countries outside North America (like Asian and European countries, including Japan, China, UK, etc)? Now I'm trying to find a site from those regions that catalogue LEGO sets.
Also, the credibility of the statistics on brickset, such as how many having the set, is not ver strong. I'm not a user there, so maybe it might change, but you can't check which users indicated that they have a set. Also, there's no stopping a user from going around and falsely claiming that they own a set.