Without taking sides

Without taking sides I have a question.
How is it that a politician can take money from a source, use that money for a particular purpose expressly wished for by that source, and then when that source pleads guilty to some heinous crime the politician on the radar donates that same amount of money given in the past to some unrelated charity of his/her choosing.
Somehow that makes it okay?
Why is that acceptable recompense?

How much different is that to say, jaywalking to get a newspaper. When a police officer stops you for a citation you can either take the ticket and the fine pleading your case before a judge OR you can tell that police officer that you will walk back across the street at the corner with the light according to the rules AND you get to keep the paper, read it, and then hand it to a homeless person on the other side.