It is all too easy for us in the know to know where to get information on the owners of an aircraft once its hull registration is known. I doubt many Joe Public will have any idea G-INFO or similar exists so wouldn't go looking for it. It would therefore be understandable for Mr Morse's action in following the aircraft.
What ever happened there after......
But the legality or otherwise of Mr Morse being on the airfield is largely academic, since the pilot has not been prosecuted under the ANO (or at least the main offence seems to be murder, which is not covered by the ANO)