Writing anything in the part of a visa application form about a criminal record means instant rejection (unless you're recently convicted wife of ex-pm Thaksin Shinawatra). Perhaps the pile of money they paid to the UK was covering that part of the application form and the authorities didn't see it.

There's a silver lining to Thakin and his wife. They have been the seed of many a protest, like the one that passed my office on its way to the British Embassy this morning (I think they're still there).