Well, I guess it helps to know that I was winning in this one. With 36 seconds remaining to play a knight ending, he completely ignored my offer like it was a joke, and that is how I played it. I should have avoided making the offer and the time-trouble.
After the game, I was naturally upset at myself for simply not marching my king to the middle of the board in a position Fruit evaluates as 0.0. I played b4, but then the knight has to stay on b8, that is the point of the position. I knew this after the game, but in time-pressure it’s difficult to remember the point of a position, let alone find a realistic plan.