Actually, isn't it the UK citizen that avoided paying the tax? It's a tax on what the individual purchases, collected by the company for the benefit of the UK government. It has nothing to do with Apple's earnings.
Actually, it's all to do with Apples earnings.. If they weren't earning above £79,000 (I think!) then they wouldn't need to pay VAT and wouldn't need to register for VAT. It's up to Apple, not the consumer.