I'm very sure this has happened to everyone at some point in CFA, TCO, etc. If not, then I firmly believe it will happen inevitably.
Anyways, as the title suggests and with that. When you see your opponent become inactive during a cf, especially when you are short on time, for how many seconds/minutes would you be willing to wait until you simply abort/leave the game?
It's because I ran into these situations on TCO before this blog is made is that I implement a personal policy to abort games if the opponent was inactive for at least five minutes.