The coach confessed!

[verticalStripes]

First of all, I wouldn't have one official watch game film with a coach. Allow your league commissioner (or interpreter) to do that.

I saw a coach run a shift like you described for decades and nobody called a foul against the offense.

The offense is allowed to shift when in a 2 point stance. So, the question is "how" they are shifting.

If they are poping up like they are practically making a veritical jump, then no way. Otherwise, it may be legal.

Also, most coaches will continue to "push the envelope" until this called. If you are going to flag it, make sure you point out a specific individual that made the shift illegal, like right tackle number 78. Don't tell the coach that entire offense shifted illegally (although that may be true).