Spooky I was just listening to this.
The light flashed brighter, the stone 'exploded' and the debris traveled away from the light.
Looks to me like a shot was fired, antitank rifle or similar perhaps rather than a 'bomb'.
Read that twitter thread for some keks.
Think that is a little light for the job. Something more like 20mm firing HE.
Lahti L39 perhaps.
see >>16651248
This one?