THIS you faggots, THIS!
Lelouch's Geass was initially somewhat well-intentioned, as he could have ordered Suzkau to simply "escape" or "get me out of here" instead of telling him to stop trying to kill himself. And before you bring up what he said at the shrine, learn to read between the lines and realize everything he said there was bullshit.
Kallen was just doing her job as a pilot by destroying the enemy.
Neither one had any fucking idea FLEIA even existed, let alone that it was on the Lancelot.
Suzaku was going to get himself killed before firing it.
Geass does not make you do the absolutely best thing to follow the command in every situation, it makes you do whatever you THINK is the best thing at the moment. And why did Suzaku believe firing FLEIA would help?
BECAUSE THAT JEW LESBIAN WHORE HAD JUST TOLD HIM VERY SPECIFFICALLY THAT FIRING THE GODDAMN FUCKING NUKE WOULD SAVE HIM!