A double attack (a sideline from my game)

Yes, this is a fork, not a double attack.
The whole puzzle falls down after 2...Kd7, when black will have the resource of 4...Rc8. 2...Ke7?? is a blunder that loses on the spot for the reason you provided. Best is probably just 1.Qxa6.
~TO


It could hapen in the game LydiaBlonde vs kuhfighter