Travelled 5 hours in 1st Class , fed and watered but no ticket inspection on board, can confirm ticket selling on board did occur in Cornwall due to
PA▸ for someone to collect their ticket they were sold after boarding at a shack left with ATE. The Paddington barrier line staff didn't perform any better - by accident I put a ticket a few days out of date in it which gate correctly rejected for the member staff to open it and wave me through ! I did not realise my mistake until half way across Paddington concourse
I understand equipment is not infallible but even a check in just 1st Class to evict any chancers would be something.