Agree entirely, Leake's ERA is unusually low for a pitcher of his type and even if he maintains it for some time, it will eventually rise.
However, some posters seem to attribute Leake's good year to luck (not referring to DD), and with this I don't agree.
Fangraphs shows the pitch distribution for a given pitcher. Leake is using his change up and curve more, and is relying on his harder stuff (fastball and slider) less often. And hitters are swinging at more of his pitches outside the zone and hitting them less. His new mix of pitches seems to be more deceptive.
So he's not exactly the same pitcher. There have been adjustments that seem to be working.