True enough. But pieces of debris or possibly protective heat shielding tiles coming off and trailing the orbiter is not. That's what needs to be looked at. But again, note that NASA has specifically mentioned that seeing "bright blobs" falling behind the shuttle as it re-enters is something that is seen even during normal re-entries, as the plasma around the shuttle builds and then "blows" off as it travels.
The video I saw last night did NOT show BLOBS. It was on a northern California NBC affiliate,and I saw "sparks".I don't know how else to describe tiny points of light that came away from the shuttle and then fell away.