As Tom Clancy puts it "you can only be betrayed by someone you trust, everything else is just business".
My perspecitive is a little different. When I set up my company, money went out of the door quite quickly, and in particular to a young woman I'd hired at 12 K per month after chatting to her in a ocffee shop. Looked just like the "real-life" stories you get in trashy womens magazines about a dodgy husband who ran off with the wife's money.
But I told my wife about it all of course, and actually I was more stressed about it than she was.
So I ended up telling her more about the company's transactions than I think she really cared about.
As it happens we've both been in employment where it would have been seriously illegal for us to tell the other about some aspects of our work, so couples do have secrets in their work, quite legitimately.
Nowadays, I don't bug her with individual transactions, but that's not the same as "secret".
As a smart City lawyer, my wife is in a rather different league to a Blair Babe, but the fact of the matter is that if I wanted to hide a big cash flow I could, even though she knows enough ways to execute dodgy transactions to fill a whole Sunday newspaper.
I'm not dodgy, but the nature of my business like many others has lumpy and somewhat random cashflows. One bank had failed to pay a big invoice with the excuse "oh, is that an invoice ?", then sent us a pile of money.
Given that Mrs. Jowell is neither smart, nor has any experience of business, with all due modesty I would have no difficulty whatsoever pulling the wool over her eyes, and to be fair as a minister she could do any number of things I would never detect.
By far the easiest way would have simply been to tell her nothing. Ministers are under a lot of time pressure, and unless they were worried, one of either sex would only be too happy if the bureaucratic crap of life like tax returns was taken care of by a trusted person.
Although a Blair babe, she's a bit "old labour",to whom almost any money making activity is dodgy.
Also her husband would know that anything to do with Italian politics smells bad, even on the rate occasaions times it is legit.
Thus he may genuinely have been trying to protect her and/or trying to avoid rows at home. I'm pretty confident that my wife wouldn't object to the rather dull activities of my company, but our first major row was over different perspectives of of how do deal with a defective co-worker.
To get her to sign documents, he'd have to have lied to her, or perhaps worse deceived her by using jargon she wouldn't quite understand. Although dumber than the things that live under my fridge Mrs. Jowell is an important person who reckons she has "common sense", ie no real understanding of anything, so confusing her would feel more of a betrayal than lying or withholding the truth.
When the truth became clear, she'd have ejected the shit she married without any hesitation, wouldn't you ?
Thus the flaw in Mrs. Jowell is that of poor character judgement, which is supposed to be something she is professionally good at.
However, I don't think there's anyone round here who can claim we've never been over-generous in our assessment of the quality of the person we love.
Of course, we don't know what she wasn't in on it.
But I doubt it.
It's just too nakedly corrupt, and given the nature of the people involved, even a BB would have spotted it.