I also think it's better to try and retain a consistent position whilst cycling, unless cicrumstances dictate otherwise. Some of those cyclists were riding like it was a race. Too risky.. either ride in the cycle lane or ride primary - I would have chosen the latter due to the poor cycle lane design and the fact my speed would have been more in line with traffic flow. Plus, it would better deter the kind of atrocious driving you saw here..
Perhaps the lane was closed at the moment the KIA driver crossed the sign. In that case he simply doesn't know yet that the lane is available again. As a consequence, everyone past the sign could think you're selfish (while you aren't). You could indicatie and explain that the drivers on your left are free to merge along...
This is where the poster lives