I'm not convinced, Mark. In Mick's case, the UKBA gave a written undertaking to curtail the Spousal Visa ... and are - or ought to be - duty-bound to see it through!
As for "bigger fish" ... Mick is a taxpayer - the SAME as most of us - including Damien Green. And whilst the latter's income as a Government Minister is likely to fall within the 'Supertax' bracket - it doesn't automatically confer any "divine right" upon its recipient to be singled out for special treatment. Taxpayers' money is there to serve the public ... and the UKBA is a Public Service!