Lord Error
Insane For Sony
Yes, I think they should have prepared his character better for that moment.You didn't think when he put a gun to slumdog millionaires head that was a sign he was unhinged?
As for the helmet yes I assume he was aware, slumdog millionaire told him it wouldn't work on him. I think it was just waived away as "life finds a way" ie chappie figured it out.
As for the helmet, I really think Chappie should have figured out something else for himself. Or (ideally IMO) nothing. He'd use his knowledge to save Dean ad transport his consciousness into robot's body, but there would be no saving for Chappie. I think the first ever self-conscious robot's sacrifice and then a man living through a robot would send a stronger message than whatever they concocted for the end.
It's also weird but it seems the alternate ending was the one they planned all along, but then dropped at the last moment. Recruiting 150000 police as was stated in the original ending made zero sense to me, until I saw that in the alternate ending, they had thousands of Chappie copies being made, so that much police was recruited to stand by if those robots decide to go berserk on humans.