I know that last year Joe Gibbs threw out a challenge flag when the opposing team had twelve men on the field and the other team was penalized. So, penalties can be reviewed. I don't know if delay of game (or lack of) calls can be reviewed, though.
The Bills took a major step forward in that game, even if it was against Miami. Miami had everything going their way, and Buffalo was playing like the team that started 0-4. Before, the Bills would have collapsed and been humiliated (see: