First of all, toast, you were dumb for moving a topic to spam assuming it will become a spam topic in the future, instead, you should have deleted the spam from the topic when the topic didn't have any/much posts which was off topic. You did a wrong action in shifting the whole topic into spam where the content of the topic wasn't really meant as spam, it's the staff's fault if the spam isn't wiped out rather than not cleaning up the spam when needed, and in the end when all the spam is hilled up, you will just shift it to spam. Both the spams and staff were wrong here. In the first place, it must be spams which should be taken into consideration, and necessarly warn the people who repeatedly does it.
So yeah, this rule needs a bit of enforcement.