He cites first that there is over heated rhetoric on all sides .. and no one knows who's responsible for the firebombing and the temperature on all sides has to come down and that unfortunately Donald Trump leads in raising the temperature.
None of that is saying Donald has caused nor is responsible responsible for the firebombing.
Unless you want to admit obama has caused and is responsible for Ferguson .. et al.
He is implieing that Overheated rhetoric by Trump is an indirect factor in the firebombing.’Think what you want but it is clear to me.