I played on a server where we had one guy AFK for more than one campaign, who never got auto-kicked. Inactivity kick was clearly on, because I say the message from many other people being kicked. The player in question was not 999.
Bug in inactivity kick
Another bug in inactivity kick:
Sometimes when loading a map I am “Dropped due to Inactivity”. I also believe this is the cause of the “client read past end of server” and “client disconnected for unknown reason” disconnects when loading maps.
hmm maybe on the phone and giving the mouse a twitch when the warning msg appears? just a possibility…
Traditionally, the inactivity drop can only be avoided by “walking” your character. I remember starting out as a sniper and gettting booted all the time, because even tho my crosshair was moving, I’d still be stationary in the same spot for 2 minutes or whenever the inactivity drop was set.
From what I’ve noticed spawn inactivity is handled differently from inactivity away from the spawn.
Didn’t seem like it. He got tk’ed and lay there dead for one whole round 
I guess the spectator inactivity timer can be set differently from ingame…
Mouse input doesn’t count as activity, which I think is stupid. One time I was playing 1 vs 3. Me being axis vs 3 Allied, all n00bs. I was on the Axis MG42 Tower by the Allied Command Post in Fuel Depot, typing, telling the Allied n00bs what to do. Then all of a sudden I’m dropped due to inactivity. So I guess typing isn’t classed as activity.