The site is trading illegally by failing to provide a postal address for returns (unless such information is provided at the time of purchase). However the owner hasn't sought to hide his address from Nominet's Whois lookup service. It's here:
http://www.nominet.org.uk/whois/lookup?query=foundthatfilm.co.uk
A quick look at Google Street View shows that address to be a mid-terraced private house on a pre-war estate. So it's obviously a one-man business, run from home.
The 'terms & conditions' the website show that he's recording films off the telly and then selling them on this basis:
"We supply on a collector to collector basis, e.g. you pay only for the time and materials to compile the content, as the content itself is supplied free"
http://www.foundthatfilm.co.uk/epages/es133404.sf/en_GB/?ObjectPath=/Shops/es133404/Categories/TermsAndConditions
Such a statement doesn't invalidate copyright law, which he's clearly breaching. (You're only allowed to record TV programmes for 'time shift' purposes. It's illegal to record them for any other reason, such as offering them for sale on that website).
My guess is that you probably would get your film but it might be a poor quality copy. However you'd be supporting copyright piracy by buying from him.