Any guesses as to why there may be a hour or so's delay on the GVA-LHR 735 tonight?

Tried all the sources of info I can, but can't find any answers so thought I would turn to the fonts of wisdom on here.

The outbounds LHR-GVA appear to be running on time, as do all the other return GVA-LHR flights - just can't think offhand a good reason for a delay on one specific flight being recorded now, and I know it will bug me all night and I won't find out any real reasons at the airport.

BA0723 GVA LHR 14 JAN 07:45 14 JAN 07:45 Actual
BA0725 GVA LHR 14 JAN 10:20 14 JAN 11:05 Actual
BA0727 GVA LHR 14 JAN 12:15 14 JAN 12:29 Actual
BA0731 GVA LHR 14 JAN 15:15 14 JAN 15:45 Actual
BA0733 GVA LHR 14 JAN 16:50 14 JAN 16:50 Estimated
BA0735 GVA LHR 14 JAN 18:40 14 JAN 19:49 Estimated
BA0737 GVA LHR 14 JAN 20:45 14 JAN 20:45 Estimated

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BA0724 LHR T5 GVA 14 JAN 06:50 14 JAN 06:58 Actual
BA0726 LHR T5 GVA 14 JAN 08:35 14 JAN 08:40 Actual
BA0730 LHR T5 GVA 14 JAN 11:45 14 JAN 11:57 Actual
BA0732 LHR T5 GVA 14 JAN 13:20 14 JAN 13:29 Actual
BA0734 LHR T5 GVA 14 JAN 15:05 14 JAN 15:05 Estimated
BA0736 LHR T5 GVA 14 JAN 17:00 14 JAN 17:00 Estimated
BA0738 LHR T5 GVA 14 JAN 19:25 14 JAN 19:25 Estimated


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Edit - umm, ignore this, it looks like the delay has suddenly cleared itself - back down to 18.48... Maybe a typo in the system