I had guessed that Nintendo would step in and offer up a statement about Nintendo Russia's CEO before the week closed out, and for once, I turned out to be right! Nintendo Europe has offered up a statement on Mr. Haddaji, and it seems they're taking the allegations very seriously.
"We are aware of a video uploaded to YouTube recently in which Nintendo Russia’s General Manager, Yasha Haddaji, is seen losing his temper during an altercation with an external vendor in charge of a Mario Kart livestream. Mr Haddaji’s conduct and choice of words are most certainly not in line with our company values. We are also aware of further allegations that have appeared in the wake of this video and are now running a thorough investigation. We take these matters extremely seriously and will not comment further while we are running our investigation."
It seems we'll have to wait for the investigation to end to get an update on the situation. Good to know Nintendo has stepped in to properly take care of the situation.