Were do you put your King?

Today I saw a game and in the endgame with was draw the famous R + N against rook endgame came the following position on the board.

Were should white goes with his King? In the game white took the Knight on e3 and resigned.

 Yes she did. Isn t it remarkable for a 2300 player?

It must have been terrible time trouble. 

I think these kind of endings induce mistakes more than others.

In her defense....it is easier to see the draw if already know/suspect there is a draw in that position....like in this puzzle, we were already suspicious....but hard to see it in an actual game, I likely would have missed it in the game, maybe even most of us would have missed it in the game?

a free piece at the cost of the game. how ironic. I do that myself more than often.