If he really has the video, it's a simple situation to me. I'd calmly say, "I have you on camera, I have the St. Pete PD number dialed up, give me the mangos back now or explain how that's not you in the video to the police."
The real tragedy is this wasn't some dude coming into the neighborhood, this was his neighbor. It's exceedingly likely the words in this video are the most they've spoken to each other since they've both lived there. All too common here in Florida; nobody puts down roots anymore and new neighbors stay strangers for far too long.