My totally worthless, layman's opinion of this based on what I know, combined with 10 minutes of googling and what's been written is as follows;
Although there was no written contract which both parties signed, there was a verbal agreement - which as far as I can tell is a contract, and can it some circumstances be upheld in court.
https://londonlawpractice.com/how-to-enforce-a-verbal-contract/
To me, even though it was verbal there must be some evidence that this agreement was undertaken, presumably the website / code he wrote exists somewhere, and that could be produced in court.
So from the court's view. on one side, you have the claimant, who wants his money for the job, on the other side you have the defendant who presumably didn't pay, because the work was not up to standard, and he's potentially not liable because the work completed was essentially not completed / satisfactory.
As much as I believe you when you say this guy produced a pile of nonsense - I actually think he might win the case against you. Simply because; you agreed to pay him 8.50 an hour but didn't.
Even though he did some poor quality work for you, in weighing up the balance of probabilities - he still did produce work, and I think a judge would award him some cash for that..
Either way if I were you I'd get a professional opinion pretty quickly, or just pay the money - otherwise it could get a lot more expensive.