> Plan: shoot some people in the group you want to leave, striking fear into the rest.

The exact same actions could've been terrorism with this as the plan, but it sounds more like an angry drunk than executing on a premeditated plan.

Contrast that with someone like Dylan Roof, who would match the terrorist label much better:

> A friend recalled a drunken Roof ranting one night about his unspecified six-month plan "to do something crazy" in order "to start a race war."