I think the odds are it was. But again, nothing has been confirmed. It takes time for LE to arrive due to the distances involved. An hour or two head start even on foot would still make life hard for those pursuing especially if the wind is hampering air surveillance.The longer this goes on makes me wonder if it was even them that were spotted.
My guess is, and that is all it is, LE will make their presence known in as large an area as possible throughout the night. Try and exhaust them and try and force them into giving up.