Clarification needed on Encroachment vs Ilegal Motion

[Forksref]

I've never heard encroachment being defined as anything other than being in the neutral zone. You may have a foul, but it would not be encroachment.

"Just prior to the snap" is not enough info. Was everyone set for 1 second? Backs and ends can reset if they move and they are then reset for a second prior to the snap. Motion fouls are live ball, throw the flag and play on.