Low probability does not mean zero probability, and the vast majority of an investigator's job is dealing with low probability events. Journalists want them to make definitive statements about things that occurred just hours earlier, and their experience says that don't yet know enough to make such a definitive statement. Give 'em a break :)
Given how widely known this tree at Sycamore Gap was, you’d have to be the stupidest person alive to accidentally cut it down. There are literally no other trees nearby.
