If a car is in the habit of driving the same route pulling the same illegal speeds every morning for a month, why weren't the police waiting?
If the guy is claiming diplomatic immunity, he can still be expelled as persona non gratta.
Then there's the generic medical drama. Will the character in the bed have a seizure and the doctors call for a crash cart? Of course. Will a baddie try to attack someone in the hospital? Naturally.
Real departments pull people off cases when they threaten to go nuts. And they sometimes assign chaperones if someone threatens to kill a suspect. Certainly the threatener becomes a "person of interest" when the suspect ends up dead.
Not a great episode, but almost no Ziva or Sloan soap-opera, so better than most.