One of the announcers on the Fox broadcast said it was today (around the time they mentioned their low SB total of 55). They did win 2.67 more games than their OPS differential would predict. But that is not a very large difference. Even if we drop them from 88 to 85 wins, they still make the playoffs.
I looked at all teams from 2010-2014. In a regression, team winning pct was the dependent variable and OPS differential was the independent variable. Here is the equation
Pct = .5 + 1.3246*OPSDIFF
The Giants had a .699 OPS and allowed a .679 OPS for a .020 differential. Plugging that into the equation gives a pct of about .52649 while they actually had .54321. So their actual pct was about .0165 higher than predicted. Over 162 games that is 2.67 wins.