Hmmmm......don't suppose we'll ever really know what happened for real there but I personally find people who litter really annoying. A new phenomena has emerged in the last year or so which I call 'thoughtful littering'
...the litterbug neatly places the piece of litter on a wall or on the ground instead of chucking it down. It seems they think that because they have
neatly placed their cr*p somewhere then its not really littering (in their strange little world)
This seems to be what happened in this case.....