Again, this guy works for UEFA, the creator of "No to Racism" and still says that word? That he was speaking his own language makes no difference whatsoever. Negro/nigger is well-known derogatory word in English, yeah the official UEFA language used in CL games.
A lot of black people have been hurt, degraded, beaten and threatened with that word. Pierre Webo played in Europe, who probably has experienced racism first-hand on football pitches, by that exact same word. You don´t get to chose how a person of another race should react to that.
It´s retarded AF by a UEFA 4th official to even use it, more so on a football pitch in an official CL game. That word can bring a lot of negative emotions/memories out of an individual. The whole setting is messed up too, he´s pointing to him and blatantly saying negro. In another setting he might´ve got clocked. People mention other black persons who don´t care, maybe they haven´t experienced what another black individual has.