Trudeau's thinking goes something like this: rules and standards are meant for people who are bad and who break rules and standards; Liberals are good and don't break rules and standards hence can go to a "pay for play" evening because they are not going to be influenced by what anybody says or does.  If they appear to have been influenced by doing something done or heard, it's only because they were going to do that anyway.  They certainly appreciated the money the nice business people brought to the party but it had no influence and they can't help it if bad people's minds are in the gutter and misinterpret their actions.  There, he's a clear as a bell.  If that doesn't convince you, it's because you're not trying.