That is a nightmare! I hope one of you got his license plate number and reported them. Drunk or senile are the only reasons I can think of for a person doing that.
Elderly unsafe drivers can be reported confidentially to the state DMV as outlined here:
Official Website Florida Department of Highway Safety and Motor Vehicles
I don't know how a big SUV like that could even get ONTO the cart path there!
Thank goodness the driver was able to see the truck coming and didn't meet him by surprise on a curve or hilltop.