I get that these thing are private affairs, but calling it banter is plain wrong.
The man is clearly a bigot and will find it hard to get employed. However, I wonder how many football managers' messages have some of these undertone and how many racial slurs are made by managers and senior players to young players up and down the country? Football is still endemically racist at the top level, though they will try to air this out as a singular bad apple that is miles away from the average. I fear the average is closer to Malky Mackay than we would like to think.