Compare with successful launch video
>>Seems something went wrong even before booster cut-off and staging. See 02:37 min. into this video of the launch, something can be seen detaching from the rocket and spinning around just before the internal shot where the "gravity indicator" suddenly rises and then the bouncing starts. 2 seconds later the debris cloud can be seen.
>According to http://www.russianspaceweb.com/soyuz_launch.html stage 1 is at 117.8 seconds, and the payload fairing is at 157.5 seconds.
> Interestingly, the emergency escape rocket jettisons at 114 seconds. I didn't know it was that early.
Hmm .02:37 min is ...120 plus 37, or pretty much 157 seconds...but before I leap to a conclusion, the video starts rolling before actual launch. Engine ignition is at approximately 0:40, lift off at approximately 0:44, which makes the object seen at about 157 less about 40 seconds after lift off (i.e. about 117 seconds after lift off) which means that it's not the fairing, but most likely the escape rocket jettison caught on camera, followed shortly after by what should be stage 1 separation.
Compare the video with the (normal ) Soyuz Launch video for the launch that carried Tim Peake up to the ISS [ISS] Launch of Soyuz TMA-19M with British Astronaut Tim Peake - look at 2 minutes 50 onwards at quarter speed to see the escape rocket jettisoned (at 2:51) followed by Stage 1 separation (at 2:53 you see the exhaust trail change).
If anything, to my non-specialist eye, the escape rocket jettison looks fine on the failed launch video, then we cut to an interior view of the Soyuz to see the astro/cosmonauts being buffeted around, so we don't see the Stage 1 separation, but we cut back to see the immediate aftermath of the separation, which doesn't look like the nice normal symmetrical Korolev cross.
Many thanks for that link to the Russian Space Web Soyuz Launch timeline.