That is a lame excuse.
Rodney King was an asshole who was recklessly driving drunk on his ass endangering the lives of innocent people.
Nicole Brown was a dumb, social climbing gold-digger who married OJ for his fame and money.
In both cases, they put themselves into the situation they ended up in.
But the argument can be made that King deserved the ass kicking he got, legal or otherwise.
It's pretty hard to make the case that Nicole Brown deserved to be butchered like an animal, and as such her butcher should go free.
To try to use one to justify the other is descending into desperation to pat black people on the head and tell them "No matter how shitty your behavior ever gets, some of us benevolent white folks will always be here to coddle you and tell you that nothing you do is ever wrong or your fault."
Not only that, but you'd think they'd be sick of Rodney King types making their neighborhoods unsafe shitholes to live, to the point that teaching them a lesson with an ass-whoopin' would be something they'd get behind.
Lastly, what evidence do you have that "Rodney King cases" were resulting in acquittals time and time again?
Are you claiming that the LA cops were out targeting blacks for ass beatings while letting white reckless drunken drivers off with a pat on the behind?
Not sure I'm buying that.