The couple of additional Chiltern trains that are using platform 3 and 4 at Oxford because they are too long for platforms 1/2 are causing all sorts of headaches on those two platforms that are already stretched almost to the max during the peak hours.
I watched this happen yesterday evening on http://www.opentraintimes.com/maps/signalling/oxford
when the affected Chiltern train lost 6 mins through waiting for Platform No.4 to become free. I thought the better option would have been for the train to leave from Platform No.3 as that wasn't in use at the time and there were no trains approaching that would need to use it (the Chiltern train concerned having been turned back via Hinksey Sidings). However, I am aware that we don't really know whatever else was going on at the time.
Nothing better than trainspotting from your armchair