Given tickets have restriction codes on them, and they're so incredibly simple to look up, this is one particular problem that shouldn't be an issue at all.
Absolutely right! It shouldn't be an issue, yet we see a lot of evidence that it is, and that tells me that thing son the railway haven't got any better, support wise, than when I was in the middle of it all.
(In fact, I know it hasn't, as I'm still in touch with various people in the industry who I used to work with and who spend a lot of their time reading this very forum as they can get more accurate information from here, and faster, than they can from their own managers. These are the better staff who don't necessarily believe what Joe Bloggs tells them at the signing on point or in the messroom!)
Even if people are all of a particular belief, it simply takes one of them to say 'let's look it up then'. No need to even look silly, as you can say 'I thought it wasn't valid, but it looks like it is - good day sir' and probably won't have caused much of a delay.
Again, you are quite correct, but that seems to go against the whole ethos of the railway. In my day, even managers got things wrong, and most of the briefings I had to sit through were poor and almost always contained incorrect information. Challenging things you hear and think are wrong but to no effect soon becomes demoralising! It's tempting instead to keep quiet and just follow the official line in order to cover yourself and preserve your employment.
If this hasn't changed much either, it's also going to be a big factor in the 'I don't need to check 'cos I already know' attitude stakes.