Catherine Greig will spend the next eight years in federal prison not because she loved James “Whitey” Bulger, but because she helped him evade capture during 16 years on the run. It’s a fair sentence, reflecting her central role in enabling Boston’s most notorious criminal to evade justice for the better part of two decades. As US District Judge Douglas P. Woodlock declared at Greig’s sentencing, “We’re all responsible for what we do. We all make choices.”