There was a passenger EMU (last year?) where one of the later cars derailed and rerailed on points leaving Liverpool Street. The driver was unaware until the guard informed them of some rough riding but didn't spot anything amiss when they eximined the train from a platform.
IIRC it was only when the people responsible for maintaining points took a second look (after their first failed to fix the signalling indication?) that it was realised what had happened.
There was a Birmingham - Southampton Freightliner at Reading that came off and re-railed itself in 2012. It left a trail of damaged track circuit cables across the lines to the west of the station, causing severe disruption, yet the driver remained completely unaware and wasn't stopped to examine his train until Worting Junction, west of Basingstoke, after S&T had been out to examine the failed track circuit and concluded there must have been a derailment. The offending wheels jumped back on at the next trailing point following the derailment site so the damage was confined to Reading West Junction. Bad loading of a container and a 'twist fault' in the track geometry at the junction was to blame.
https://www.gov.uk/raib-reports/freight-train-derailment-at-reading-west-junction