>Indeed, studies in medical malpractice have shown that doctors and hospitals that promptly admit fault and apologize are less, not more, likely to be sued for malpractice.

There's a huge context difference here. These studies are dealing with the doctor apologizing to the patient (or their family) and being less likely to be sued by that patient (or their family). This has a lot to do with emotions and how the patient or their family feels about the doctor and the doctor's actions.

In the case of Amazon here, it's essentially making a statement to the world that could be used by anyone as part of a lawsuit. I imagine the class-action lawyers looking at these things aren't going to let their feelings about Amazon change their minds.