If I am not mistaken FL has one of those statutes that permits Open Carry only while lawfully engaged in fishing/hunting/camping.
In some states it is legal to open carry a rifle on a sling in public. Pointing it at/across a public street from a semi-concealed position, as the suspect was, isn’t legal in almost any situation, in any state.
The reporting placed the gunmans position across the street from the golf course, so yes you’re correct, but only in a semantic sense.