Actually it's quite different, which I alluded to above. Last year the Dolphins were big underdogs at home, had lost two in a row and four of five to start the season, and the Steelers were coming off of two wins in a row.
This year the Dolphins are on the road, won last week, and the opposing team lost at home last week.
The Falcons aren't going to lose two games in a row at home, much less to the Dolphins in the second game.
Now one has to consider the spread, which is 12.5 points. That's less than two touchdowns. Now ask yourself the likelihood with which the Dolphins could get beaten by the Falcons in Atlanta by two touchdowns or more, given the above context.