For those who find the balloon theory preferable to the thing-on-a-string theory, or for "string theory" proponents willing to prove themselves wrong in the interests of truth, explaining what would cause the appearance of what looks like a string in several frames would be helpful. "String" is:
Only visible above the object, not below.
Only visible when zoomed in sufficiently that a string might become visible.
Similar artifacts never appear elsewhere in the video. (If they do and I'm missing them, anybody feel free to point them out.)
If there is a string extending above it, it might still be a balloon inflated with regular air. If the apparant string can be shown to be something else (presumably some sort if video artifact) that should help clarify what we're looking at...