Illegal motion?
 

Tailback takes two steps towards the LOS then turns and motions outside the end. I know the rules says any back may go in motion as long as it is not towards the opponents goal. I have never seen this flagged and we have never called this illegal motion but the defensive coach went ballistic telling us in his last game it was called against his team. I'm curious if other crews call this illegal motion?

That's not exactly what the rule says.

And I doubt the coach's account of what was flagged.

You already specified the substance of the rule. If crews call this illegal, that would be improper, right? So what's your real concern here?

It's not a matter of when you can go in motion forward, but of being in motion forward at the snap. In the example above, when did the snap occur?

The culprit here is that you believed a coach. Either A) he's making the whole thing up, trying to rattle the new guy, or B) he completely misunderstood the explanation of the foul in his previous game.

In short, don't EVER give any credence to "but they called it that way last game". Ever. You will hear this all year, in every sport.