Normally I will ask is the dcer anyone's friend first. If there is a friend then Im sure he/she will know whether he is trying to reconnect back as it shows when your friends connect to steam and dota 2.

If the dcer is solo playing, then the remaining players can give a certain amount of time lets say 5 mins pause for the dcer to come back. If he doesnt then continue the game.

Asking the right thing is the solution.