The devil is in the detail with Rog’s statement (as it is with all interpretation of legislation) - whilst the two might not get added together, as Rog has already stated “time working in a non-driving job can’t be counted as rest for a driving job”. So, in practice it amounts to the same thing, despite the wording.
Bottom line, If you’re on the road and not properly rested, you’ll be at risk, and where there’s an accident, the “my mate reckons…” online post, whether from TN or elsewhere, will not help you under questioning from the CPS Barrister. If someone has died as a result of the incident, the Barrister will be on a mission to make you look like Peter Sutcliffe’s best mate.