Yes, I did see it. I have heard of the incident in passing but have not looked into it. There were a number of minor Union raids and scouts into that area of Florida, usually in search of lumber, so it is certainly possible. You might try emailing either Olustee Battlefield or Fort Clinch State park to see if the staffs at either of those places can tell you any more about it or direct you to someone who can.
Let us know what you find out. I would be very interested in hearing more.