He was penalized, the whole thing was somewhat unfortunate because it was evident to everybody that Marcus was not indending to cheat
This is more or less the comparison. Marcus had no intention of breaking a rule, nor did he think what he was doing was wrong since the game was in his eyes and his opponent's eyes already over.
Platinum threw his game away because in his eyes they were gonna surrender on the subsequent turn anyways. My point is that if Platinum just made 24 standard picks that the game had a chance to be playable. Idk if DM would've booted later in the game, but he was clearly present for pick stage and the subsequent turn or he would not have made 24 picks and accepted his own team's surrenders.
IE: Marcus streamed his game and by rule definition cheated. Platinum picked 4 picks on a playable game and by rule definition threw the game.