I thought putting Top Secret documents in a waste bin in a Park was called Making a Drop. Your controller (who would have been following you) can then do a Pick Up and hurry back to a Foreign Embassy to Microfilm them all ...
But to be fair to the chap [I've only met him once and he seemed pleasant enough], his eccentric habits reminded me of an incident which occurred forty years ago.
John Birtwhistle and I were walking up the Caledonian Road, as you do, when we noticed some waste bins outside the offices of the Movement for Colonial Freedom overflowing with interesting looking papers. Many were telegrams, from and to the African National Congress and such like. This was the era of apartheid and even though telegrams would have already been read by Our Agents and Theirs, it seemed rather careless to put them out on the streets. So we gathered them up and disposed of them properly - I forget how.
But I did not dispose of some other interesting things. Blank sheets of notepaper with the crest of the House of Lords. Oh, what delight!
"Dear Fiona, May I request the pleasure of your company for Tea ...."
I guess Adam Werritty would have found a quite different use for them.