The saving papers IMO is kind of ok, but the teacher can still come back and say the kid could be faking the paper and it was not done in time. (Think it hasn't happened? Think again.) But e-mailing the paper to the teacher? (I would also be cc'ing yourself)... This,
THIS, is a beautiful end-game solution. Everyone who has this issue with a teacher, take NOTICE and do it.
agnes!