IME, zero-tolerance policies are highly-selectively enforced; they are quite convenient for administrators who want to act arbitrarily, because lack of action is less likely to be challenged if it doesn't lead to someone else getting injured, but any time action is taken (however flimsy the justification) the nest of zero-tolerance policies for (for drugs, including anything that could loosely be interpreted as associated with drug paraphernalia or drug culture; for weapons and violence, including anything that could loosely be interpreted as being suggestive of, related to, a simulation of, etc., a weapon or violent act; etc.) provide a convenient excuse for any response disproportionate to the substance of the act.
Zero-tolerance policies aren't an alternative explanation to administrators acting arbitrarily including based on racial, religious, or other prejudiced animus, they are an enabling mechanism for that arbitrary action.
Kids get suspended for less in schools, now -- racism or not. It's easier (and more likely) to explain these outcomes through hardened, zero-tolerance policies.
>When I was 14 I hung out with (Caucasian) kids that lit things on fire in the park.
And...I'm assuming you didn't get caught because you used discretion and weren't doing things in a controlled setting (e.g. classroom) or putting others at risk.