Ymb,
No error, it was straight fraud and he should go to prison.
He claimed for his kids living in his London house, except school registers show they were in Rochdale at the time.
On being caught, his contemptuous excuse was
// I maintain that the existing rules (about 'routinely') are poorly worded and not fit for purpose when it comes to modern families like mine”. //
In other words, he interpreted ccassional visits by his childred as routinely living with him. If such a blatant fraud was committed by a member of the public, they would be jailed.