[Smokey]

In my humble opinion it does appear to be a combination of your speed and direction and his abrupt change in lane.

Not easy to lay blame as certain factors are missing like your speed.

Should you be travelling at that speed passing stationary traffic?
Were you considering the hazards like other drivers not keen to wait in the queue? (People do like to jump into the right lane, go all the way round a roundabout to their exit to avoid waiting in the correct lane)
Were you driving to the conditions of the road ie heavy stationary traffic vs speed vs weather/visibility

The other driver, did he check his mirror before pulling out?
His indicator cancelled pretty quickly so wasn't visible to you.
He judged your speed incorrectly (although your quick lane change may be a factor in not seeing you)

I think overall, the odds are more in his favour on just the video alone although he has to take some responsibility for pulling out into traffic especially at such a laboured speed.

All just my opinion but tough one for the insurance company who might just settle for @the driver behind is at fault' scenario.

A little bit of impatience from both parties I would suggest.

Hope you are both ok though, quite the impact.