I havn't seen the Telegraph article, but I presume that the inference is that if this was Miller's Norseman seen over Woodley, it then proceeded on a direct track to Paris which would have taken it clear of the Bomb Jettison Area.
This is unlikley as there was a special cross channel exit route to France between the coastal AA Batteries, which would have put the Norseman close to the Bomb Jettison Area. (See Roy Nesbit's article in Aeroplane, date unknown)
The weather was poor, and there is also a story that Miller's aircraft landed enroute at the Friston advanced landing ground - reason unknown, weather/fuel?
We can only guess at the truth, but the sighting from returning Lanc over the Jettison Area does seem very credible.