One more bit of evidence in support of Tannehill. Most people realize that the longer a sack takes, the more likely that the QB is at fault. This article from Football Outsiders looked at that:
http://www.footballoutsiders.com/under-pressure/2013/under-pressure-sack-breakdowns
Looking at the QBs with 20 or more sacks, there is an interesting breakdown:
QB Short Sacks PCT Normal Sacks PCT Long Sacks PCT
17-R.Tannehill 17 53.10% 12 37.50% 3 9.40% 32
7-G.Smith 5 17.90% 8 28.60% 15 53.60% 28
3-R.Wilson 8 29.60% 9 33.30% 10 37.00% 27
7-B.Roethlisberger 8 30.80% 9 34.60% 9 34.60% 26
11-A.Smith 9 37.50% 8 33.30% 7 29.20% 24
12-T.Brady 14 60.90% 4 17.40% 5 21.70% 23
3-C.Palmer 13 56.50% 5 21.70% 5 21.70% 23
2-T.Pryor 3 13.60% 6 27.30% 13 59.10% 22
1-C.Newton 6 28.60% 5 23.80% 10 47.60% 21
3-B.Weeden 5 23.80% 6 28.60% 10 47.60% 21
5-J.Flacco 7 35.00% 7 35.00% 6 30.00% 20
The young QBs (except Tannehill), G. Smith, Wilson, Pryor, Weeden, Newton all have more long sacks (likely their fault) than short sacks. The veteran QBs, Brady, Palmer have more short sacks. Roethlisberger, A, Smith, and Flacco are evenly distributed. Tannehill takes very, very few long sacks. In fact, despite being sacked most overall (by far), he has the fewest number of long sacks. When compared to QBs with similar amounts of experience, the difference is striking.
We now have three different looks at the sacks. Two attempt to assign blame by observing the actual plays. One uses the timing of the sack (therefore not subjective). All come to the same conclusion. To top it off, the team confirmed the problem by making OL changes in mid season.
I don't know why anyone needs to look any further for blame.