Today I saw this question in the front page of Meta:
Some user seemed to have edited it 6 hours ago, as the question footer said in the front page: "discussion 6h ago user221135 1". But in the question history I saw no such activity. Nothing seemed to have happened in that question since long ago.
What had actually happened was that the user, who didn't have edit rights, spammed an old answer of mine. His suggested edit got rejected as spam by two other users. In the end, nothing changed.
So a spam suggested edit made a question bump to the front page. I see this as an incorrect behaviour.