I have no desire to argue over semantics. However, if you were to single out someone in this manner in the UK and use their colour, religion (yes religion) or nationality, etc., it would be defined as a racist attack.
For example, if I were to call someone a Paki b*stard, Chinese w*nker, Indian f*cker etc etc., whilst beating them up, I would probably be prosecuted by the police for a racially aggravated attack.
When the assailant used a word to describe the victim, i.e. British, he was defining that person based on his nationality.
As I said, I'm not going to argue semantics with you. I would leave it up to the courts to decide if it was racially motivated or not, my guess is they will. However, lets wait and see.
Some definitions of racism also include discriminatory behaviors and beliefs based on cultural, national, ethnic, caste, or religious stereotypes.[2][6
Finally, lets not forget the history of these two counties........