I believe him. There's plenty of power-tripping fuckwits who get desensitized enough that they enjoy it, and /pol/'s the exact type of place that would eat up some Dick Marcinko-esque black ops stories. As far as "The West Side Boys" I'm not sure it's a false claim moreso that it's just a clumsy attempt at censoring a swear word (and yes, "nigga" is a swear word, otherwise they wouldn't bleep it out on network TV and the radio) by using an appropriate synonym.
The fed post from earlier also got me thinking. Everyone on /pol/ complains about alphabet agencies going there all the time, but have they ever stopped to consider that some of the alphabet people are actually true believers? This is the same FBI that kept constant tabs on left wing activists and tried to blackmail MLK into suicide, and /pol/ likes to brag about how a lot of them work high end jobs but hide their power level. If you really want to go tinfoil, I bet a good chunk of those "fed" infiltrators are legit white nationalists who use the "undercover" excuse as plausible deniability.