I'm intimately familiar with that piece of airspace, and there's no way this was a bottle rocket. Aircraft pass over that beach *at least* 500 feet up, I know, because I used to fly along the beach underneath them when they passed overhead in the offshore "helicopter route" at 150 feet.
The article in the link claims they were 6000 feet up, and that sounds much more reasonable. And also much higher than even a flare would get.
Just curious. What altitude do professional pyrotechnics reach? Amateur rockets can reach a mile, but they would not be leaving a trail at their maximum altitude.
You flew along the shore in front of LAX westbound departure?
I don't see that figure in the article. Where did it come from?
And if they'd made it to 5K feet that would also imply they were well out over the water, over the outermost reaches of Santa Monica Bay, probably at a similar longitude as Pt. Dume or thereabouts. Where'd the device come from? Too far down range from any of the Channel Islands. Someone mentioned Pt. Dume itself - possible. Or a boat?