External Link/Members Only'Track defect found near derailment site - report'
The RAIB, which is continuing to investigate the derailment, said it had received "several reports of rough riding at the location of the derailment from passengers on other trains".
The continuing investigation will now consider elements including how that section of track was inspected and maintained, the condition and maintenance of the embankment, the weather conditions and how effective any hot weather mitigation measures were.'
But not, it seems, why the fuck the 'reports of rough riding' weren't specifically investigated.
As I recall this isn't the first time that reports of rough riding weren't investigated properly. The fatal 97 mph crash at Potters Bar in 2002 comes to mind.
Furthermore it would have been of general public interest if the reporter had given an update on the condition of the two seriously injured passengers
Footnote
It is now reported in the Times that the dislocated rails were filmed two hours before the crash.