The only situation that I can see a draw occuring in espionage is when both players are left with one piece each. Even if you are left with the stronger piece, you can be left in a situation where you cannot capture the opponent.

This has happened to me once, back in the era of IYT and indeed it was with Nothingness, who had the weaker piece, but had forced the draw by his thought out final exchange. In this case if a player refused to accept a draw, I'm sure Fencer would overrule this, and no need for any game knowledge to see this.

As to stalling, and no capture in 50 moves, well I don't accept this. There are two people in the game and I will keep capturing, even if not captured in 50 moves! If a 50 move no capture rule was implemented, then white would always lose in a long dancing play from the start, or would be forced to make the first capture. So black wins simply by avoiding capture in the first 50 moves!

Yes, there are some jokers who keep offering the draw when losing, guess they are hoping you hit the wrong button :)