None whatsoever.Folks more experienced with these matters than me: Is there value in submitting a formal subject access request ASAP to try and protect CCTV footage in cases like these?
CCTV does not record audio so would not prove anything that could aid the OP. Even if it was working, pointed in the right direction, recording sufficient resolution, etc., it would at most show that the passengers concerned had had a conversation with the relevant staff members. They could have been asking the guard about a connection, return train times, or a million and one other things.