Unlike your
opinion of "Jury Nullification" being the reason, a police officer named Mark Fuhrman was
proven to have lied under oath about never using the "N" word. A recording of this moron officer bragging about how his "Department was so tight they could pull black people over & fabricate evidence to arrest them" is what did it. That clearly demonstrated racism as a possible motive for framing OJ by planting evidence. That is why he was acquitted, even though he was guilty.
"The tapes include many racist slurs and remarks made by Fuhrman, including uses of the word "n----r," descriptions of police brutality perpetrated on black suspects, misogynist slurs and descriptions of the harassment and intimidation of female Los Angeles police officers by male officers. Portions of the tapes were admitted into evidence during the 1995 O. J. Simpson murder trial. In the tapes Fuhrman also made many references to the "planting of evidence" and implied that police brutality and evidence planting were common practice in the Los Angeles Police Department."
Suggested reading (even though it will make you uncomfortable):
https://en.wikipedia.org/wiki/Fuhrman_tapes