Reading the article, it appears the alleged slur was spoken in Thai language (“I can understand Thai. He scolded me so clearly: “Ni**a! Get up!...).
I wonder if the actual N word was spoken in the English vernacular, or if some Thai language equivalent was spoken. It also begs the question if the referee correctly understood the (English language) racial implications of his use of the word.
Personally, I've never heard a Thai use the word and I don't think they understand it - they usually revert in reference to a Cadbury or Hershey's product.
If a Thai bloke is telling me something in mixed Thai/English language, and I indicate my understanding by uttering "I hear", in which language should the listener interpret the utterance?