Many of them are called to intentionally be short passes. When you see receivers blocking downfield as well as other plays it is obvious that many of the short passes are called to be that way. On check downs by the QB, you’ll typically see him look downfield and then progress to a short pass as time goes on.

So we can know on many of them. If you want to nitpick about the handful of check downs, so be it. I do not believe the majority are check downs.