(Apologies but in this description I give Charlbury timings rather than starting point timings)
Situation on arrival at Charlbury station for the 0724 train to Oxford and paddington, looks like the 0712 to
Worcester was 15 late (unknown reasons) at Oxford, expected Charlbury 0737 and is being held at Wolvercote as the
0724 is already on the single line running approx 5 late. However the 0724 is obviously attempting to make up time and clear the single line as it comes into view it is obvious that it is running very fast and indeed fails to make the platform stop, finishing with the rear powercar on the Oxford end platform ramp. 10 minutes to change direction and reverse train, 5 min to load passengers and start off again, eventually passing the stationary 0712 HST▸ at Wolvercote, eventually arrived oxford approx 15 min late.
Guard gave excuse of railhead conditions at Charlbury but frankly a lot of passengers did not believe this for a number of reasons, absolutely no evidence or leaves on the line or ballast within sight of the platform, no appreciable delay until this event, no problems after this event. Rails damp but temp well above freezing.
Interestingly the knock on effect of this was that a subsequent Worcesterbound train was terminated at Oxford and the 0938 train to Paddington (0837 from Worcester) was started from Oxford, however FGW▸ gives on their webpages rather different excuses:
06:00 London Paddington to Worcester Foregate Street due 09:26
This train will be terminated at Oxford.It will no longer call at: Kingham, Moreton-In-Marsh, Honeybourne, Evesham, Pershore, Worcester Shrub Hill and Worcester Foregate Street.This is due to signalling problems.
08:37 Worcester Foregate Street to London Paddington due 10:59
This train will be started from Oxford.It will no longer call at: Worcester Foregate Street, Worcester Shrub Hill, Pershore, Evesham, Honeybourne, Moreton-In-Marsh, Kingham, Charlbury and Hanborough.This train will run short formed with 3 carriages.This is due to an earlier broken down train.
I agree the webpages weren't too accurate, but I was caught up in this mornings problems myself - and just to indicate how things can go wrong; The first down train suffered a train fault in the Slough area - the driver received a warning of a locked axle (which could be quite serious) - following investigation it was found to be spurious and probably caused by excessive wheelslip en-route. As a result of this the train arrived Oxford about 20 mins late and the decision was made to hold it at Wolvercote to allow the up HST through the single line. It would then terminate at Evesham to form the back working from there at 09:01.
After it had arrived at Wolvercote the incident involving the Charlbury overrun happened. I'm sure relevant people are observing a download to see whether the driver or conditions were at fault - all I can say is that ALL routes were prone to slipping today due to the severe winds and heavy rain - advice was sent out to all drivers about the situation at Charlbury following the overrun.
That meant the down HST was sat at Wolvercote for nearly 30 minutes and as a consequence was nearly an hour late. The plan then changed and it ran through to Worcester to work the following train back (usually the turbo) pretty much on time. That was a sensible decision based on how events turned out, but meant the cancellation of the 08:37 until Oxford.
So, the 08:37 Worcester-Paddington train being described as cancelled due to an earlier broken down train was, depending how you interpret it, accurate. Had the locked axle fault not happened, that train would have passed through the single line before the other service that had the problem at Charlbury, and ran on time to Worcester.
It just goes to show that there might be more than meets the eye sometimes.