It's quite apparent there's something appearing to come from the shuttle, but whether variations like that are normal I certainly can't say. Any commentary a layman would have on any video I think would be sheer speculation.
I'm no expert, but I've seen the shuttle come in early in the pre-dawn hours over Texas before...it is a marvelous sight, but there's no secondary objects or things dropping from it. A big ball of light with a contrail.
There was a small cross-section of tile just behind my church (in Kerens), and a nondescript metal chunk driven into the ground at the A of G a block away.
Prayers and condolences to the astronauts and their families.