Apparently there was a high expectation and relatively short time set by the immigration agency.
British people living in sweden needed to produce 5 years of tax receipts and certificates from employers. Within 2 years. (I don't know what happened if you had been living there less than 5 years.)
But if he did what was asked, he should have been okay.
There would have alot of contact from migrationsverket. There must a lot that is not reported here.
Migrationsverket are hardline. Anyone who knows anyone who's had dealing with them knows that you do what they say. No-one minds when it is immigrants from outside europe. I have a feeling that here, this couple thought that the authorities would be lenient because he is british.