A couple of things....you did slow down, but it appears that it was simply taking your foot off the gas. Not much of a speed drop. However, watching the body line on your hood in relation to alignment with to the solid white shoulder delineator (that's painted stripe chuckles) you fail to even make an attempt to ease left one iota. That's the part that got ya right there.
I hafta agree with jk on this one.
One thing a video shows, especially when moving at speed, is that the human eye sees a lot further and discerns more at distance. You had approx 400-500yds, it would appear, from the time the strobes came into view to the time you passed the scene.
Again, watch the alignment of the body contour line on the right side of the hood. You did not move over, at all, even though if the truck in lane 2 was still next to you, you'd still given them a couple feet of so.