First of all, yes, I'm including a time when he was injured, which is relevant because that was an injury he had right before he was coming to the Red Sox, thus there was a chance it could have affected his play here. Secondly, his career stats include the 2004 and 2010 seasons, which significantly boost his stats in the AL East parks, and I'm sure other parks as well.
Looking at his 2010 stats alone really isn't helpful in the discussion of whether or not this was predictable. But if you look at the numbers for 2010, they are all-around better in just about every park. He had troubles in Yankee, Target, and Rangers stadiums, but besides that he's in the .900- 1.000 range everywhere else. He even hit .869 in Safeco for SSS. Yes, it absolutely is small samples, but when when it is a small sample over several stadiums, it becomes a much larger sample to look at.
Even compare his career numbers in all stadiums to his season numbers in all stadiums. He has far more .600 to .700 ranges in those samples. It looks to me like all signs seem to point this being an outlier year.