From reading the comments on this and other threads it seems that some guards and RPIs are very knowledgeable about the rules and are determined to enforce the letter of the law.
I don't think it's a case of 'determined to enforce the letter of the law' at all. I think it's a case that guards/train managers/ inspectors are charged with doing a difficult job that includes ensuring that travellers have the CORRECT ticket and charging correct fares, or reporting offences as appropriate.
(maybe the rules should be changed?) ..
That seems to be the answer given far too often these days, people frequently display the... 'I want the benefit of the very substantially reduced ticket, but I'm not prepared to abide by the conditions that allow the reduction'....in other words; 'give me all the benefits, but the rules don't apply to me!!'
and forget that they are meant to be providing a service to the public..
Good customer service includes assisting re-education in a great many cases.
The 97% of the travelling public who do pay the correct fare and travel without problem frequently thank inspectors for making sure that others pay the correct fare and sometimes even write to us to express their appreciation too.
If the original post is correct then why not smile, point out the passenger's error, and offer an excess to the anytime single fare, which a previous post states would have been 80p..
Let's play Devils' Advocate then, the reason why this would not be the correct response is because
IF the traveller
was actually trying it on they would have learned nothing other than; if I try it on again, I'm likely to get away with it again.
Furthermore, if they had got away with it, that member staff was just saving up conflict for a colleague who might simply apply the rules on a subsequent occasion and the traveller object because of past experience.
The passenger (customer) would have been happy, more likely to travel again, and would tell her friends of the good service received rather than being ripped off by the nasty railway.
As
Yorkie made perfectly clear in his post, the rules accepted by the traveller when they purchased the Advance ticket state that it can only be used on the booked train and if not, the correct remedy would be for staff to charge a new ticket.
The traveller (the law never refers to us as customers) would likely be happy to travel again, but would check their ticket more thoroughly in future and would be much less likely to try to 'rip-off the train operating company'.
I made clear earlier, I think that there was a degree of discretion that might have been applied in this case to achieve a better outcome, but none of us were either of the two people directly involved, so cannot be certain exactly what happened in the interaction