That is the reason he ran it out, because he knew he had some room there to go.
This game, Bills left a lot of points out on the field, and had to rely on some huge plays you can't expect to happen very often. The punt return obviously, but also the tipped TD catch by Sherfield, that pass was terrible. Bills created their own bad breaks, but also took advantage of the big breaks they did get. And the fact that Tua really couldn't connect in that 2nd half. Bills will have to play better overall to keep going.