I think he gave the speech exactly as Wilson wrote it, until Wilson himself walked in, at which point House went off-script in order to tell Wilson (implicitly) that he should forgive himself for what he did.
See, I wondered about that. If he did that does little to help Wilson "falling on his own sword." If it would've been Wilson's speech -just read by House- then the AMA still could've came down on Wilson, that's why I figure House may have started off using Wilson's words but then "punched up the language" to make it more plausible for it to be falsehood -clearing Wilson of any possible "wrong doing."