If this is still live, it would be good if you could give dates so it can be investigated further.

However I have also need a number of glitches in this space. Not so much on one-way flights, but for example I have noticed differences between the "FlightList" screen (the tablet friendly version on the front of the UK's version on BA.com) and the "F&H" screen you get via BA.com/flights in most browsers. I think the App uses FlightList too. Among other problems that I have seen is that it is not pairing up all flight options. I noticed a EDI-LGW flight that was offering £37 flights when the immediately proximate services on LHR and LCY were all over £200 as was the earlier LGW flight. Lo and behold this LGW service wasn't showing on FlightList at all, so a whole heap of people would have been unaware of this service. The so-called "fx" screen, used for Multicity, does seem reliable from my searches.