After two games, the Dolphins' defense has been a sieve. There is absolutely no reason to think the Bills will not score at least 40.
Could Miami's D suddenly find their stride? Sure, it's possible. Could Josh slip on a mat on the way out of the tunnel and not play? This too is possible. But, if you play the odds, neither is likely to happen, however remotely possible they are.
If your measuring stick is based on completely shutting down Hill, Waddle and Geisicki for a full 60 minutes, then in fact, you are correct. The Bills will fail. On the other hand, if the measuring stick is simply to win the game, I do not find any likely scenario where this does not end positively.