Gov. Healey yesterday went further than most other Dems in suggesting that Biden  consider withdrawing. But “carefully evaluate” isn’t the same as “irretrievable,” a word usage that remains a mystery. … Adrian Walker thinks Healey seems ambivalent. Or as a friend told me: “I agree with you that the Governor’s ‘irretrievable’ is an ambiguous choice of words. Also suspect that was an unambiguous choice to be ambiguous.”