Board Game Arena

I have this game (https://boardgamearena.com/13/schottent ... =739925451), and even if I win it, there someting that I don't understand.

Why I don't win the 1st stone ? (with my tactic card, I have 3 of the same vs 2 card)

You have a 9 in hand so, as hands are hidden, it could be in his.

As a 9 is missing, he could also have a 3 of a kind.