According to the Herald, the reason behind this is that Incognito was considered by his teammates to be "an honorary" black man.

Well, I've spoken to multiple people today about this and the explanation from all of them is that in the Dolphins locker room, Richie Incognito was considered a black guy.

Eagles Richie Incognito, who allegedly used racial slur toward Jonathan Martin, was 'honorary' black man in Dolphins locker room Published: Nov. 06, 2013, 4:51 p.m.

A former Dolphins player reportedly said Richie Incognito is considered an "honorary" black man and more a part of the black community than Jonathan Martin.

Police docs: Richie Incognito seemed to think he worked for NSA, attacked man at gym The former Bills offensive lineman had a major-league episode at the gym this week ...

Doritos Packed a Spider-Man Suit Into a Bag of 'Incognito Doritos' for Charity The only downside is you can't actually eat while wearing the suit.

Richie Incognito was reportedly involved in an altercation at a Florida gym and then placed in psychiatric hold.