Experts are never wrong, especially if they wear white lab coats, I would never challenge their conclusions.
But you were so absolutely sure about it. It was as-if you had done the calculations yourself and proven them wrong.
You wrote: "There is no way that rock has enough gravitational attraction to hold that smaller rock in orbit."
...Anyway, if they had imaged the two asteroids over a period of time they could have simply observed the smaller one going around the larger one. ie, seen it in various different positions with respect to the larger in separate still shots.
That is still my belief. I am not saying the rock isn't orbiting the big rock, just that Gravity alone does not adequately explain it.