I wondered about that as well. Are they saying that someone tried to shoot it down five days earlier?
So the theory would be something like either they were practicing/training (?) or that the tape shows an attempt at another aircraft earlier.
The first theory begs the question, why would they be so foolish as to train in such a populated area? That would be stupid, begging to be seen/reported. I still hold terrorists are fanatics, but not stupid. I don't think it would've been someone training.
The second theory begs the question, how did they miss? Why wasn't the missile heard/seen/reported by anyone? Also, if you took a shot, you would immediately execute your escape and evasion plan. They would not have stayed around or come back just a few days later to try again.
That's why I think investigators looked at this, said yes, it is consistent with the launch of a MANPAD. But it apparently is not definitively a launch. Also, there is apparently nothing else to indicate a launch took place, and nothing else to tie it to the crash a few days later.