Exactly. "Trash talk" is generally, in my experience anyway, a mutually agreed upon exchange of meaningless threats and insults. With both sides willingly participating and both sides knowing that the other side doesn't really mean it.
This was not mutual, and one side was not a willing participant, and the threats sure didn't sound meaningless to me.
What I really don't understand is why the police don't enforce some "personal space" limits -- set up some barricades or police tape or something and keep the protesters and murder-threateners at least a few feet away from the police, if not more. This business of letting the murder-threateners get right in the face of the cops just seems so wrong.