Damn Good Point there!!!
I agree with you, and I wanted to add that, The mom should have told him to always cooperate with police officers, if fucked up in the head or not, not to basically try and argue with an officer and disobeye the law or a direct order.
But
yes 
The mother messed up since the beginning to let him drive and probably get crazy and unpredictable with his mood swings and thoughts since he was ill in the head. The mom should have known better, look for example.. my friends mother had a son that was a schizophrenic and never allowed him to drive! Especially by himself!!
Schizophrenic, bipolar, drunk, on heavy drugs etc.. only bad and the wrong decision are made.
"They could have just shot his tires out or they could have handled it differently. They didn't have to kill him."
yeah, and he and his handlers could have handled it differently as well: the whole world is not here to cater to and accomodate insane/mentally ill/erratic people, and to always give them the benefit of the doubt in sketchy situations. and if he was that crazy then why did he have a drivers license?