I agree, Fizzbuzz.
We are all human and capable of losing things, but most teachers will have personal procedures to minimise this.
It's amazing how pupils will swear blind they handed in their books though. There's no way of proving one way or the other until the book shows up, but in 95% of losses, it is the pupil who has it.
I simply won't take work from a pupil in the corridor, in the staff room or wherever. It has to be in the classroom, where I have a place for storing their books and papers.
We don't have locked classrooms in our school, so they are always free to put in their work outside of normal lesson times.
For coursework, pupils do it on the computer nowadays. If it gets lost, the most they have to redo is their graphs. Although we don't have coursework nowadays (yeah!), I had little sympathy for those who said they handed it in and was nowhere to be seen. The reason for the melodrama over the extra effort was because they were genuinely starting from scratch (having not previously put pen to paper).