For many Australians her failure to disclose her relationship with a former bikie boss is just filling in a bigger picture. It's a picture of someone whose judgement appears not so much occasionally - but in fact generally - to be wide of the acceptable mark.

Sadly for Adam Bandt it has revealed his own weakness and lack of judgement.

Everybody makes mistakes. It's a part of life. No doubt Senator Thorpe would like this saga to be seen as one lapse of judgement. But it isn't.

If the reports are true that she and the bikie used an encrypted messaging service to communicate and deleted them regularly that in itself is worrying. Why would you feel the need to do that? How many people do you know who do that? Nobody does it inadvertently. You make a decision to install the app, multiple decisions to use it and multiple decisions to delete messages. At every stage you make a conscious decision to hide your communications. There's always a reason people do that.

She should have had the brains to see the risks and declare the relationship herself ... devoid of that common sense she didn't. Perhaps that's being too soft. Perhaps she was well aware of the risks and consciously decided to keep quiet.

If that wasn't the case in the first instance it certainly was when her staff raised their concerns with her repeatedly. Hopefully the Senate enquiry will find out just how many times they did raise it, only to have her consciously make the judgement that she should reject their advice.

Turn your mind to the situation that would have unfolded in her office. A staffer might raise something initially and you reject it. They come back to the issue the next day or week. You reject it again. Another staffer raises it with you, you reject their advice as well. Every time it was raised she made a decision to ignore them.

These conversations wouldn't have been along the same lines as "I'm going to the cafe, do you want a sandwich?" No staffer, however close to their boss, just saunters in and casually mentions you're making a big mistake. A mistake that could come back to bite you and your party. The first time it was raised the air might have been one of friendly concern. But not the second. The second time a staffer raises it they are in effect saying you have made two mistakes. The first is the one you were warned about and advised to remedy by disclosure. The second mistake you are raising with your boss is that she was too stupid to listen to you the first time and so now you are forced to wipe her face with the dish cloth and raise it again. You get my point. These were not nonchalant chats.

Then when the committee hearing from the federal police about monitoring bikies sets a date for the meeting, when the agenda comes out, when you walk into the room, when the subject comes up. At each of these moments it enters your head that you have been advised to disclose something and you decide not to.

So for the Senator this isn't a one-off error of judgement. It is a determined and recurring pattern.

Her leader responds by saying he has made her resign a party position. Talk about wilted limp lettuce! He tries to cover himself by saying if it becomes clear more should be done he will. How about take her off all committees for a while and this one forever?

MORE AMANDA VANSTONE:

In dealing with the explanation as to why he didn't know, Bandt says his chief of staff was told but didn't tell him. He tells us this was just an error of judgement by the man. Errors of judgement seem to pop up around Senator Thorpe. I hope what Bandt says is true and the staffer isn't copping the flack to protect his boss. If it is true then Bandt might consider the position of his chief of staff. It may be a one-off error. But it's not the volume of errors but the substance that counts. If a staffer always mispronounces a name it's an error, but not one of substance. Not telling his boss about Thorpe's undisclosed friendship is a very substantive error.

Some reporting of this sorry saga hints both that Thorpe has no real understanding of her error and that she feels she is still on high ground. Deluded is the appropriate adjective. She says defiantly that she didn't disclose anything from the committee meetings. Not the point at all. If she had it would make the whole saga much much more damaging. The error was in not disclosing the situation to her leader and more importantly to her colleagues on the committee. It's the lack of respect shown to the Senate committee system, its rules and conventions and to her colleagues.

How can committees expect the federal police to trust committees with sensitive information if they can't be sure that all relevant disclosures by senators have been made? Trust is important in all aspects of our lives. Damaging the confidence all witnesses have in committees is damaging the parliament.

Turn the situation around and imagine you're a private citizen, maybe working in an accounting firm that has a bikie or two as clients. You come across information critical to law enforcement but you're worried they've been infiltrated. Now you know that a senator didn't disclose a bikie relationship. Will you speak in confidence, on camera to a parliamentary committee?

Members of the public who vote Green must be wondering how all this happened.