Said extension hopefully to have a picket fence and anti-tresspass mat.
Electric fence and machine gun emplacement would be even better for these types. The sooner they realise a working railway is not an adult playground, the better.
If nothing else, it is simply not fair to place a driver in the position that they see someone at the line side, or perhaps even close to the platform edge, when they do not expect it.
Graham - you should've given
BTP▸ a call to deal with these numpties, they should take trespass fairly seriously. You should forward your photo to them for consideration/future reference - you have a clear face pic of the older guy.