Ah this one, I assume?
Yea Kizaru, much like majority of the Marines like Fujitora/Akainu/Garp/Sengoku/etc, follow what Smoker said:
"
once a pirate,
always a pirate"
I forgot who Smoker said that to, it was either Crocodile, Doflamingo or Law. That even if they're not recognized as pirates, they'll still continue acting like pirates, thus you gotta treat it as "once a pirate, always a pirate", em mfs don't change simply because they're not recognized as pirates.