Hopefully SXM has a similar policy in place as the US FAA. Here is a link to the FAA pages concerning UAV operations: FAA UAV policy page.

In the US drone operations within 5 miles (or 10 miles in some cases) must be coordinated with the FAA tower and permission can be granted for a specific operation for a specific time with specific set of restrictions. Permission may also be denied.

Hopefully the UAV operator was in contact with the PJIA tower and coordinated his photo flight with them.