When I first saw the title ' fast jets in the sky ' my initial reaction was " well, better than underwater ".
As a ( pro' ) aerial photographer, I find it easy to believe you could see afterburners in the distance but not hear them.
The point about NOTAMS is a good one but not everything is advertised, likewise I'd be rather despondent if ALL military radio traffic could be picked up by spotters with scanners !
As said, it IS near fireworks night, so the only other thing I can think of is someone with a really serious but still off the shelf set of large rockets ( though I can't recall seeing firework rockets leave a glowing back end as described, more of a trail of sparks, so these must have been expensive and quite possibly hazardous ! ).
I'd imagine the people who experiment with proper rockets, taking months and lots of money to build the things, would distance themselves from ' launches ' anywhere near this time of year as they take things seriously, and would have to file NOTAMS.