Look, we have a strict policy about spoilers. At first I thought banning 3 weeks for a spoiler was outrageous.
But it really isn't. A ban doesn't prevent you from leeching. It doesn't even stop you (IIRC) from adding new favorites. Your old level is restored when a ban expires. So really all it does is stop you from uploading/posting comments/posting on the forum.
I care just as much about civility as I do about spoilers. So I think a ban of seven days is a modest and acceptable punishment.