Sorry, I am being pedantic, but whatever an individual wants a word to mean, we are stuck with what most people think a word means and that is the meaning given formally in a dictionary, which in this case means, fraudulent and dishonest behaviour.
As I said I am not defending Williamson, bullying is a nasty way of of getting your own way by violence and intimidation, and given the general acceptance that this kind of behaviour is considered unacceptable in any circumstances, especially for someone in the public eye like this, it is also a very stupid to thing to do, because, as has happened here, once you are accused of it, especially formally in a goldfish bowl like parliament, the door marked Exit swings open and you are on your way out. Your career overshadowed by bullying claims for life.
However this kind of behaviour, however heinous, us not corruption.