But again, I broadly disagree with the concept that there can be a verbal offence that is so serious that you feel you must stop the game, but is also so minor that it's only worth a warning. You wouldn't stop the game in order to warn a player that he's approaching a dissent caution and I don't see anything in the laws quoted so far in this thread that opens up that window for a team official on the side of the pitch.
Yes, I agree there is technically a loophole that a referee can use if he decides between blowing the whistle and reaching the coach that it's not actually worthy of a yellow. But that's a getout if you stop the game when you shouldn't have, not a refereeing choice that we should be actively encouraging.