When WotC sells a flawed product they have a responsibility to correct it. (Within reason of course.)
Andy (and the rest of R&D) has a responsibility for the quality of his work. If he messed up, then he should fix it. If he spent half the time he spent bragging about 3.5, on answering the FAQs from the boards, it would have made a major impact on the clarity of the game rules.
The one mitigating factor is that - apparently - he doesn't get paid to clarify the unclear rules he was supposed to fix in 3.5 (or created in 3.5). And I even blame him a bit for that. I have seen no indication that he's tried to make it part of his job. (Understandably of course - you don't want to ask your boss for extra time to do what he's already paid you to do, and the game designers, [with a few honest exceptions] are notoriously loath to deal with their mistakes.)