Clandestine 1:

From the rules :

The game ends when all frogs of one player are revealed on the board (no matter if they were shot or guessed). The other player gets a bonus of 2 points and 1 point for each own frog which was not found by the opponent.

So, I only took a quick glance at your game, but he had 14 points before the move. He got 5 for finding your frog, 2 points bonus for it being the last frog, and 1 bonus point for the 1 frog he had left. So that would bring him to 22 points.