Merlin was surprised to be shoved back against the wall, wincing slightly at the arm pressed roughly against his chest. He made a noise that might have been an attempt at speech, but ended more like a pained squeak. Arthur was, without question, much stronger then the young sorcerer so physically he couldn't push the prince away. Magically he could force Arthur back, but he didn't make any move to do so. He simply remained against the wall, enough room between him and the doorway for Arthur to leave.