Yep, there aren't any hints about the order, you just have to try and see since its only two possibilities, also the two letters were separated, so he can argue that they aren't necessarily be the same order. And since you can't control the GA code, he had to improvise.
There is the first GIF of the boxer when he bluffs with the right hand then uses the left, but I doubt that he intended it to be a hint.