"It does make you wonder if the finder has not broken some laws in handing classified documents to the press, perhaps they should make an example to deter it happening in the future."
Thus ensuring that no-one ever picks up anything again................. if he/she had turned it into the MoD do you think we'd ever have heard about it? That they employ incompetents who lose important documents on public transport?
"You just do not take Classified Material to your Club, Pub, or Parlor.."
Since it was found at a bus stop we have to assume they planned to read it the document on their trip or that's what they had been doing when they got off the bus.