I am not a controller but if he had said unable he would have been doing a 360 to the right. He calmly said he could pass behind the 777 and had him in sight. Situation handled. For some reason the RA caught the 777 by surprise even though their TCAS would have clearly shown the Cessna before the RA and they were advised of the traffic. Looking out the window is a good procedure in any airplane. Was anybody in the 777 doing that when they got surprised by the RA? Did they respond as they were trained during the RA? Minimum corrections are sometimes all that is required.