In the end of that sequence Michael Bidwill tells Steve Keim that it played out exactly like they thought. I took that as meaning they had thought Rosen would slip a bit and thus they might be able to trade up and get him. It is, however, also possible that the scenario Michael Bidwill is talking about is the scenario after Josh Allen was selected.
Again, like you wrote, it could have been staged. I just think that might be too much of a conspiracy theory.
1. I sure hope they aren't taking the time and effort to stage things in the middle of the draft
2. If so, Mike B has a future in acting
There is a possibility that post CLE taking Ward, the cameras captured Keim speculating on Denver taking Chubb -- and it could very well be after (off camera) they called up Denv and learned their pre-arranged trade is dead.
one reason I don't believe that, or that Allen was their QB1: why couldn't Keim have called up Indy or TB to get Allen with the same offer they were prepped to do with Denver? If Denver had agreed to that deal, it presumably was one Buffalo wasn't ready to do. Further, Mike B is quoted as saying that if Denver took a QB, no QB in round 1 for them because the Cards couldn't beat Buffalo in a trade up and all would be gone.
Finally, in the couple days leading up the draft, the hosts on 98.7 talked about Josh Rosen over and over. I think its likely that the Cards got wind that Rosen might fall, and that they might be in a position to get him.