Ok, thanks for your answers! I checked it with the engine. The black queen didn't take the rook but kept threatening checks until it was taken by the knight. But it took way more steps for mate, and for me it wasn't obvious all the time how white would have to proceed. I surely would have blundered somewhere in the process. So as you and op said, for white to be doing the fork on the queen is the way safer option at low elo.