What did Brewer see that was "evading the cops"?
He stood there and "looked scared".

Looking scared would be enough.
You really need to stop trying to portray Brewer's actions as irrational and the resulting police response as unwarranted.
Doesn't matter if it was because he thought your hero looked funny, looked scared or just had a receding hairline.

Bottom line is Brewer thought Saint Patsy was acting suspicously and took the necessary action to get your client apprehended.
Sucks for you and your hero, but you're just going to have to accept it.