Team A kicks off to team B. During the return team A coach makes contact with the official in the box. Penalty is called and marked off from the end of the play. Later in the game play goes out of bounds on team A sideline and flag comes out for sideline warning. The referee announces sideline warning - team a’s first and there is no yardage penalty. Is this correct? Do they still get a warning even after the previous foul for contact in the box?