Keller’s apologia as cited in the Public Editor’s column (not to be confused with ‘apology’!) is that he was just using Lisa’s reports as a jumping-off point for voicing his own opinions on quality-of-life, heroic medical interventions, and so on. He did not intend to attack her personally, so one shouldn’t expect accuracy about her actual statements or experiences, which do not concern him. You go to war with the strawmen you have, not with the strawmen you’d like to have.
Lisa Adams was just collateral damage, it seems; so an apology is not required. And it was her fault anyway, she was just asking for it:
she invites us to think about and debate some big, contentious issues
There is also smug self-congratulation about having “touched a nerve”.