Did Boston's F.B.I. Not Learn Anything From Whitey Bulger?

Did the F.B.I. Not Learn Anything From Whitey Bulger? “Cutting deals with criminal informants may, at times, be a necessary if unsavory part of law enforcement. But the benefits must outweigh the costs, and it is not clear the F.B.I.’s Boston office has mastered that balance,” wrote the editors of the NYT. [NYTimes.com]