You can take my finger guns when you pry them from my cold dead...wrists?

in context it seems he was threatening the neighbor with violence

It is not necessary to prove that the behavior was so violent as to cause mean terror or that the victim was actually frightened. Threat, criminal threatening (or threatening behavior) is the crime of intentionally or knowingly putting another person in fear of bodily injury.

the same way as I cannot walk up to someone and say "im going to fucking kill you" then it becomes police discretion to arrest you if they think it is credible.

happens a lot in domestics

trust me, im a lawyer