CI doc says == FALSE. Why isn't it === false?

Hello,

At https://codeigniter.com/user_guide/libra...light=form you have the comparison:

PHP Code:

if ($this->form_validation->run() == FALSE) 


Two questions from the above code:

1) The doc says that it returns a boolean result. So, why doesn't it use the "===" operator?
2) PSR-2 says that the constants true, false, and null MUST be in lower case. Would make any difference if I switch FALSE to false in the above example?

Thank you,
C