The apology itself was point-by-point perfect, so perfect that it's hard not to imagine that it was the product of professional PR advice (not that there's anything wrong with that — if I had his profile and were in his situation, I'd seek expert advice at this juncture, too.)
He offered two very different explanations for his wrongdoing, explanations that are not necessarily mutually exclusive, but just very different.
Woods' first explanation was that he had succumbed to temptation. The particular explanation he offered was that he had allowed himself to believe that the rules didn't apply to him, and that he had allowed himself to think that he had earned the right to enjoy the temptations around him. (As I've discussed here before, there's reason to think that excuse-making, and in particular the process of making exceptions for oneself, is a key component in various kinds of wrongdoing.)
The second, very different, explanation, was a medical one. Though he was vague about this, Woods said he had spent most of the last 2 months in treatment, receiving counselling and therapy. (Roughly, it seems the implication is that he suffers from addiction — namely, that he's a sex addict.)
I don't know (and the talking heads on TV don't know either, regardless of what they say) which of those explanations is correct, or whether there's some truth in both of them.) But it's crucial to see how different those 2 explanations are. The first is basically cognitive: the implication is that Wood had formulated a certain kind of argument in his head, namely an argument that said that he was subject to an exception to the rules he said he himself believed in. The second explanation is, roughly, biomedical — roughly that there is something, presumably something subconscious, in Tiger's head that makes him behave wrongly.
Now, Tiger Woods' wrongdoing was primarily not a question of business ethics. His wrongs were largely personal wrongs. But the question of what makes people do bad things is an important one in business ethics (and in other fields). So it's worth considering: is the cognitive (excuse-giving) part of his explanation plausible? Is it sufficient? And to the extent that it resonates with what we know about other cases of wrongdoing, does it point to a strategy for reducing the frequency of wrongdoing in particular contexts?