I am not an accident investigator, nor do I play one on AN.
I see a couple on a bike buzzing along minding their own business in the left lane, no other traffic around, bike was showing a tail light.
Car was in the middle lane at the junction and moved to the left (does the road narrow there?) and shunted the bike up the rear, no brake lights until after the collision.
Car was definitely not hanging around (I never was any good at judging speed from video) but was travelling a lot faster than the bike.
Only one to blame, car driver. Awaiting the result of an alcohol test.
RIP two youngsters who did nothing wrong 😞