Starting in 2001, here's how NE has fared in Miami, just for some context:
2001 (Pats finished 11-5*, Mia finished 11-5), Oct 7, L 30-10, out gained 296-149
2002 (Pats finished 9-7, Mia finished 9-7), Oct 6, L, 26-13, out gained 319-245
2003 (Pats finished 14-2*, Mia finished 10-6), Oct 19, W, 19-13 (OT), out gained Mia 332-326
2004 (Pats finished 14-2*, Mia finished 4-12), Dec 20, L, 29-28, out gained Mia 322-231
2005 (Pats finished 10-6, Mia finished 9-7), Nov 13, W, 23-16, out gained 437-365
2006 (Pats finished 12-4, Mia finished 6-10), Dec 10, L, 21-0, out gained 315-189
2007 (Pats finished 16-0, Mia finished 1-15), Oct 21, W, 49-28, out gained Mia 443-382
2008 (Pats finished 11-5, Mia finished 11-5), Nov 23, W, 48-28, out gained Mia 530-392
2009 (Pats finished 10-6, Mia finished 7-9), Dec 6, L, 22-21, out gained Mia 448-416
2010 (Pats finished 14-2, Mia finished 7-9), Oct 4, W, 41-14, out gained 400-265
2011 (Pats finished 13-3, Mia finished 6-10), Sep 12, W, 38-24, out gained Mia 622-488
2012 (Pats finished 12-4, Mia finished 7-9), Dec 2, W, 23-16, out gained Mia 321-277
2013 (Pats finished 12-4, Mia finished 8-8), Dec 15, L, 24-20, out gained Mia 453-378
2014 (first game of the year), Sep 6, L, 33-20, out gained 360-315
That's 7 wins, by an average of 14.6 points per game, out gaining Miami by an average of 84.3 yards per game.
That's 7 losses, by an average of 10.4 points per game, getting out gained by Miami by an average of 27.7 yards per game.
During that stretch (not counting this year), the Patriots have been, on average, a 12-4 team, while Miami has been, on average, a 7-9 team. So the Pats have been *significantly* better during these last 13+ years, and yet going to Miami has effectively been a 50-50 crapshoot.
Color me not surprised that they lost this game, in other words. Even when the Pats have been great and Miami has sucked (2004, 2006, 2013), they've lost down there.