We, as cyclists, know why you were riding in the road when you had a whole cycle lane free - but does he - a non cycling driver?
To him you were taking the p1ss - you left a whole cycle lane and rode well into the driving lane effectively encroaching in his space. He may be wrong in his belief, but if we understand the driver's psyche we might avoid such confrontations.
It's fine referring cyclecraft or the cycling section of the highway code, but unless you're a cylist, you have no reason to read upon on them.
I think the self-gratification artist signal and the fact you turned around at the lights was unnecessary.
Incident occurred, nobody got hurt, I would have moved on.
When he asked you to move over to the side of the road, you shoule have taken up his offer. But rather than roll up your sleeves for a fist fight, you could have educated him about why you rode where you did. Instead you pointed to the camera as if to say 'haha you can't touch me?
Of course you'll disagree with all of this, but it's an alternate viewpoint. If we understand the other side, we're more likely to get on fine.