All that the existence of these kinds of unusual situations could do is provide a *possible* explanation, or possible partial explanation, as to why the drafters included sub-paragraph (b) on day and time.
LTW would still have to show why the words "is to be determined by reference to...the day and time" don't also apply more generally, including to your case.
The idea that
"the drafters must have had these kinds of examples in mind"
could not disprove what might be regarded as the common-sense interpretation:
"the drafters meant this to apply to time-and-day-related distinctions in general, such as between anytime and off-peak fares
(irrespective of whether they had those examples in mind)".
If LTW can't find examples relating to day and time, then the argument they are using has another problem, which is why it's worth noting.
Indeed. And another notable thing to point out which renders LTW's reading illogical is that, if the date and time of travel is not taken into account then it could lead to a situation where a passenger is penalised not once, or even twice, but three times over for their misdeed (and perhaps four times over if they held a Railcard).
Imagine the case, for example, of someone holds a ticket from London to Cambridge on a weekend, but stays on until Cambridge North (perhaps under the mistaken understanding that "Cambridge" covers both, like "Cambridge Stations" might). If they were then intercepted at Cambridge North without a ticket, LTW are saying they would agree with a TOC which charged the passenger a Penalty Fare for (1) the entire journey from London (i.e. ignoring the ticket already held), (2) at the Anytime, "Any Permitted" rate, when the much cheaper Super Off-Peak rate is valid, (3) at
twice that fare, (4) without any Railcard discount. The first, third and fourth elements are more than sufficient penalty as it is.
Thus, according to that logic, the single journey from London to Cambridge North might end up costing the passenger £50.20
plus their existing ticket of £7.60 (if they went for the GA only option and had a Railcard), which incidentally would have been the same price in the first place to Cambridge North. It is clearly an Penalty so disproportionate that it is clear why it cannot be correct or intended. A Penalty Fare of twice the adult-rate "full single fare appropriate" would be £23.00, which is harsh but nowhere near as disproportionate.