No that is a TERRIBLE comparison. Just because Conor made a terrible choice in a fit of blind rage of throwing dolly's at a bus when his best friend was assaulted, does not mean he supports other criminal activities. In addition, you can't compare different criminal activities, because everyone's reasoning for doing so is different. Not everyone who is a murderer is an arsonist, not everyone who is a burglar assaults people, etc.
Khabib on the other hand is directly involved with PEDs via his best friend by refusing to do his good USADA citizen duty and exposing him. I agree that Khabib could just be willing to break the law for his own friend, and that doesn't necessarily mean he's using, but it's still highly suspect.