Presenter notes in Keynote Window Mode using Apple Script
So it turn's out it is simply a timing issue adding delay does the trick:
tell application &quot;Keynote&quot;
        activate
        show next
        delay 0.1
        set selectedSlide to slide number of current slide of front document
end tell
tell application &quot;Skim&quot;
    tell document 1
        go to page selectedSlide
    end tell
end tell