Shortcutting Shared Fate?
Assume this situation comes up (deck is played, above permanents are in play, Player2 is locked out) . It's game 3, with 20 minutes left (Player2 conceded game 1 as soon as the lock was established, and you heard him say he understood he had no outs, then won game 2). Player1 has called you over, asked Player2 for the concession and been rejected, then asks you to watch their match for stalling/slow play. Player1 then proceeds to take each turn as fast as possible–literally draw(replaced)-go, taking 10 seconds or less/turn, not even looking at the card they ‘drew’.
How long do you let player2 take on each of their turns, before cautioning/penalizing for slow play/stalling? Do you change that amount of time, as the turns progress, and no relevant game actions are taken? There are no relevant game actions by player2, regardless of the card drawn(replaced) each turn, and you stand behind player2 so you can see the card each turn, so you can verify this. While few players will verbally admit they're taking as much time as they can per turn to take advantage of the time limit (“I'm taking time to think, judge, honest!”), at some point it begins to look like slow play/stalling. Is it?
As a follow-up, let's say you decide the answer to the time per turn question is 45 seconds before you give a warning(change the times in this follow-up to match your actual answer). Does your answer change, if player2 then seems to be (silently or not) watching 40 seconds expire, then saying “Go” on second #41, turn after turn?