That is a very good question. First I would like verification that they did seize it. I have only seen one unsourced post say that it was. Assuming it was it clearly says they have doubts and want to examine it closely. If they have doubts that says a lot of things. Some very worrisome.
Something did catch my eye when looking at still pics on the CBS site—the last pic, I think #13, has captured a blue line appearing to be in the same trajectory as the “contrail.” What is that?
I saw that and I don't know. One FReeper has a theory about it here and has been asked to clarify some points about it here. No reply so far.
If that is the object’s left over true path, wouldn’t that angle to the ground be measurable?
Only very roughly if at all. There are too many unknowns. Primarily the exact position of the line in the sky assuming it can be reasonably established that it is a remnant of the flight. Position and angle of the camera that took the pic.
Thanks. I’ll try to find a source for that seizure info.