The way to run this play legally would be to be sure that none of the other ten players move after the snapper starts running to the ball. As a lineman, he cannot be in motion at the snap, true, but he only has to stop for a fraction of a second, not a full second - unless there is a shift. The one second rule applies only to shifts. If you never create a shift, by never having two guys moving at the same time, then there's no requirement about being set for the full second. A much shorter pause will do.
Unfortunately in this case, as soon as the other linemen turn around 180 degrees, that's movement and a shift has started. Now the ball cannot legally be snapped until everyone is set for One Mississippi. That doesn't happen in this play. Flag it.
Now is this a live-ball illegal shift, for an illegal shift happening after the entire team was stationary for a second after the RFP? Or a dead-ball false start, for an illegal shift without the entire team being stationary?
It appears that the entire team is stationary for a second immediately after the RFP signal and before the snapper starts running. However, in practice, we don't typically consider a huddle to be a set position - that is, we typically blow-and-throw when a team never gets set after a huddle. So I guess the question is whether this team's position at the RFP is a huddle or a true all-stationary state.