Another day, another dossier

Another day, another secret dossier stolen from an official's car and found dumped in the rubbish, then handed to the Sun. Do you not find this chain of events sounding rather bogus?
1. A Major leaves the file and his security pass in his car while he goes shopping. This has happened so often it's starting to become a cliche. In these days of heightened security, what army officer is going to do such a stupid thing. I admit it may have happened, but we're taking it in context here. It starts to stretch the envelope of believability.
2. He is not thought to be facing any disciplinary action. He allows a file and a pass to be stolen, in a time of high security, thus causing the MOD grave embarrassment, and nothing happens to him? The MOD are either being highly magnanimous, or the file is misinformation which was supposed to get stolen.
3. It was found in a gym bag. The major's? If so why was he keeping it in that, and not a briefcase, as one would expect? Or maybe it was the thief's? In which case, why would he get rid of a perfectly good bag? Likewise, if it was the major's, why get rid of a perfectly good bag? Why not take the file out and throw it away?
4. It was handed in to the Sun newspaper by a member of the public.
Why did they hand in it to the Sun, and not to their local police station? It wasn't the Sun's property. It had nothing to do with the Sun. Why take it there? Why is it the Sun that gets these discarded dossiers anyway?
Who is this public minded citizen anyway, who chose to give up these documents with no thought of monetary reward? The thought occurred to me that it might be an office worker at the MOD who was handed the gym bag and asked to drop it in at the Sun, on his lunch break, but that would be unworthy of me.
Remember, it could have happened just like the Sun, reported. There is no reason to believe otherwise.