So he allowed a much higher OPS in High leverage cases than otherwise. But it looks like he did better in High leverage cases in 2012 & 2013. So maybe he had some good luck then. My guess is that most pitchers have this kind of pattern, where they have bad luck one year and good luck the next or vice-versa (I hope I can take a look at that).
But I did look at how pitchers in general did over the years 2012-15 (with stats for each pitcher being cumulative). I only looked at pitchers who had 100+ IP in all three leverage situations, so I think that means only starters got in (or mostly starters-the only guy with under 500 total IP was Wade Davis and I took him out).
Then I calculated a weighted average (by batters faced) of the OPS allowed for all three leverage situations over the years 2012-15 for this group. There were 72 pitchers (Chris Sale was removed as well). Here are the results:
So pitchers generally do just a bit worse in High and Medium cases than Low cases (in the long run, as I combined years). So Sale might have had bad luck this year, after some good luck in the past.