Yes, I got that impression. In my case, one member of staff who did know, and was clued up (and stepped in having clearly observed things from afar), and one who was insistent that a bit of creased paper on a wall was to be treated as gospel, despite it not actually having restriction codes but instead a series of times, trains and long passages of text. And his interpretation was that you could travel on slow trains, but not HSTs... no doubt with other staff having their own interpretations. Oh, and stating that the National Rail website could be wrong as things change all the time (without perhaps acknowledging that surely a website that could change things would be more up to date than a bit of paper some years old).
You'd think it quite easy to round up all staff and inform them that there's a problem, and how they should deal with tickets in the evening peak. In theory that's all you'd need to do. Staff would know that any ticket being shown COULD be valid, and to take steps to check if not absolutely sure.
Currently I do believe staff read a staff bulletin and disregard it as they think they know better, or that the content of the memo doesn't apply to them and is about something slightly different.