I can't speak to whether there was an "announcement" of the United flyby but two years ago the Virgin America flight was announced. Unfortunately I got there late and only saw it from a distance. The United flyby was listed in the airshow program however...

I was there.

- It wasn't an aborted takeoff.
- It wasn't a go around.
- It WAS authorized. United had VIPs on board for this special flight from SFO that just went to the bridge, buzzed the bay, and landed back at SFO. I kinda wish I'd been on board to experience it. But I get nervous about turbulence.
- It was not at all close to the GG Bridge. The plane was like 1,000 feet clear of the bridge when it first approached. I thought maybe it was too high at the time and wouldn't be low enough for the first fly by.
- The shot in the video is a zoom shot and optically fools people into thinking that the plane turned dangerously close in front of the bridge. It didn't. There was at least a mile to a mile and a half separation between the bridge and the jet. More than enough space for any decent 747 pilot to handle
- As was already mentioned the flyby happened over water and a good 1/4-1/2 mile from the crowd gathered for the air show. The Blue Angels were lower and closer and flew right over the crowd for Pete's sake.
- This wasn't the first time Fleet Week had a United 747 Jumbo do this maneuver. It happened last year as well. The year before that it was a Virgin America A310, which admittedly isn't as impressive as a 747 but a bit more maneuverable so it didn't take a full minute to circle back to the front of the marina.

In summation, there's nothing to this story.

Update: The FAA was forced to put out a statement on this to clarify that the video was optically misleading and the plane was 1,200 feet clear of the bridge as it flew over. It was even higher when it left.