I think this example of speech would fall in the “shouting fire in a crowded theater” category. He wasn’t using words to express himself but to cause others to take direct action resulting in this scenario.
As for using the preceding statements before the incident, as an example if I said on record “I’m going to kill that guy”, and he is later discovered dead, those words while not conclusive proof that I’d actually killed him would absolutely be used in court against me even though they would still need more evidence besides that. The difference in this analogy is I would argue that I was emotional and did not mean to actually kill him but was expressing myself, while Trumps case was more presenting instruction to a crowd which I can’t see as being the same thing.
