Hristo, i doubt that the FW190 wasn't able to follow the Jug, he just had to go to lag pursuit to see his target.
Remember this:
The gun camera is placed in the wing, it has the same view angle up and down, while the poor pilot has that engine in front of his cockpit. And to kill the Jug the FW190 guy had to see it. That why i think the guy stayed so long in pure and lag pursuit. A few times he went to lead and took a short burst, just to switch back to lag to see if his target is still there.