Ah yes, it was her King, not her Rook. My bad. And indeed, very poor sportsmanship. I will just add that it is against her character. She doesn't normally do this kind of thing.
I should also add that the winner, Anna Zatonskih, didn't technically do anything wrong with regards to "stealing time". It's a natural occurrence in time scrambles in blitz games. She didn't intentionally do anything "illegal". It's just wow, what a horrible way to lose a National Title (in a non-blitz tournament)!
Here is the winner's response to the game...
I started the Armageddon game not very successfully and was in a worse position, which especially managed to increase Irina’s time advantage. With good defense I survived till the severe time pressure where we both had less than a half of minute.
Close to the end of the game Irina knocked her rook over and never put it back. The USCF rules say: “If, during the course of a move, a player inadvertently knocks over one or more pieces, that player must not press the clock until the position has been reestablished.”
I remember my very fast thoughts at this point: If I will press ‘pause’ and claim win or extra-time based on illegal actions… I will lose on time! The “Pause” button is a very small one on the front of the clock. So I only had 2 seconds and I didn’t have a time to do it! I know Irina didn’t do it on purpose but I had to move my rook as fast as I could. I didn’t see any other choice for me.
Irina pointed out (in her Open Letter) that I started couple of my moves before she pressed her clock. I’ve always liked to watch on YouTube how strong chess players play blitz. I was amazed how they can make good decisions in just a fraction of a second. During those games players with a 2600-2800 ratings and even world champions occasionally moved before their opponents pressed the clock. This is a common thing in blitz games.
Susan Polgar also didn’t see anything unusual and wrote that “[she] played in countless blitz tournaments and this looks like a normal blitz game to me. I do not see anything unusual and I do not think that either player was doing anything “illegal” on purpose.”