I have a suspicion that these guys might just have been from too different backgrounds and on vastly different wavelengths.
I've hung around people who I thought were jerks who I overlooked because I thought they were trying to be friendly in their own awkward and kind of unthinking way. I know I've been guilty about that myself, were people misunderstood my attempts to be friendly.
Maybe what we've had here all along was Incognito trying to take Martin under his wing in the way he'd want it done to him and Martin being completely oblivious to that because he'd never been exposed to that style of ... I guess you'd call it "mentoring" or "fellowship". Cogs being overbearing and over the top, Martin being more quiet and introverted, and both completely alien to the other's world, neither ever got the other and both handled it poorly in the end.
Cogs reputation worked against him. Martin might have been taking his own struggles to adjust to the NFL and the outside criticism to heart, and he's not a guy that lets it out.
The more that comes out, the more I think these guys were just incapable of understanding each other, and there might not have been any ill-will intended on either side, but neither was socially capable of dealing with the problem when it got to be a problem.