Good sleuthing
You definately nailed the Argentina video, which really didn't impress me. It goes to show you how "reporting" can take simple events and make them into something else (example: street lights froze, cell phone batteries died, etc).
Now, as for the original orb that was filmed zipping around; it doesn't look like LED lights at all, although I'm sure the MOD will do a thorough investigation and would be delighted to chalk it up to some kite flying youths. Until I see a better explanation; it remains "unidentified".