The timer is set to 4 mins 30 secs for a disconnect on a skins game. So players wait the excessive amount of time for the player to reconnect...or not (as is often the case).
If they wait the full 4 minutes and 30 seconds for the timer to run down then the player is removed from the game and the game loads up and resumes
but...
if there are one of those annoying 30 second advertisements to put up with then it tells the game that is has been inactive for 5 minutes, so up pops the default inactivity 'your game has been cancelled' message' and disconnects the player who has done nothing at this point but wait in a lobby because someone disconnected from the game.
The good news is the game is still active while there is someone in the lobby but it means having to come out of the game and go back in wasting even more time.
It's a simple thing that WGT could easily fix. I have no idea why a practice skins game requires 4 minutes 30 seconds of waiting in the lobby? 3 minutes is more than enough ...but at the very least cut it down to 4 minutes so it doesn't clash with the inactivity timer.