Thug is the new dog whistle word on the right used to replace the 'n' word. Thug actually means a criminal, but because conservative white men, no matter how physically imposing they are themselves, appear to be consistently afraid of any black man who is angry, no matter how justified, how provoked and antagonized.
Those angry old white men who are conservatives don't make the distinction between someone male and black who is verbally expressive, and someone who is an actual physical threat. I'm not sure they are capable of making that kind of distinction, because their prejudices get in the way.
We have not only racial and ethnicity discrimination in this country, but we have gender biases as well. We cannot reasonably expect men to be free from emotion any more than we would expect it of women or children.
This is a thug, this is a man who is using larger size and threats of physical harm to intimidate. He is actively being investigated for real crimes.
This is not a thug. This is a man who happens to be black, who is expressing anger with a member of the opposing team who not only rejected his attempt to shake hands and congratulate him on a good game, the opposing team member verbally and physically taunted and provoked him, resulting in intense words. He is not a criminal, and is not threatening anyone for doing their job.
The white thug is abusing a reporter; the black athelete is not.