It is for their management to properly oversee staff training issues, and if errors by frontline staff are being repeatedly raised & overlooked then it is management who should be the first to fall... only then the staff training issue can be tackled.
Exactly right. I always took the approach when I was in management outside the railway that a making an occasional mistake was only human, A gap in knowledge an be relatively easily rectified, provided that the systems to do so are in place.
It's a bit different if someone is making a lot of mistakes, has had their errors explained, has had refresher training and is either refusing to learn or is unable to. That is whne I starte dott hink about transferring a member of staff to a different role, or issuing warnings to them about their performance.
It does all require effective and interested management. My experienc einside GWr, although many years agoi now, suggested that quite a few managers were either not interested, not sufficiently competent at the job, or were too overloaded with responsibilities to be effective. Maybe little has changed?