Illegal Formation or Illegal participation?

[AndrewMcCarthy]

The players don't have to be within the marks at the RFP- they have to be within them at some time between the RFP and the snap.

When your player went in motion across the field, he satisfied this requirement- no foul.

The only way I see this violating 7-2-1 is if his motion still didn't bring him inside the marks. I assumed when you said "across the field" you meant he did.

I totally disagree with your association's take. Think of how many times you'd have a foul if all A players had to be inside the marks at the RFP.