false start or encroachment

[RedCisc]

I am a new official who played FB many years ago- many years ago.

The QB uses a long snap count that draws a def. lineman through the NZ but he gets back before the snap. However, that lineman's movement makes his opposing offensive lineman rise up. Is this encroachment or a false start?

I think I remember our coaches in HS trying to train us to keep our eyes down the line on the ball because this type of situation is a penalty against the offensive lineman for false start.

Thanks