I personally think he should seek with his solicitor if there is a way to claim that the bank withhold his legally acquired money for 3 months and have them pay way more than the around £9k they are trying to get away with.

Barclays is bad with legalities I had issues with them in the past but I guess every bank is... They asked me to come in and proof my address while I have an account with them for over 10 years, money comes in and out every month from my employer, I got a credit card with them as well etc etc and generally I bank with them for 10 years without ever doing anything suspicious... I found it very odd that they asked me to go in and verify me address after that long... then I read online they've done it to many others including a guy working as a bank manager with them.