When Donnie walked out of that dilapidated house, the Owls leader seemed to have suffered a complete mental breakdown. He kept letting out screams, while the upper half of his body twitched slightly under the force around his neck. The poison gas Klein had given him was astonishingly effective, reducing a professionally trained assassin to such a state. Donnie had originally asked for that small canister of poison gas to prepare for Batman. He had been worried that Batman might jump out and ruin things at a critical moment.