This made my local news yesterday. Supposedly, the picture was taken near a rest stop off Alligator Alley in the Everglades. Anything is possible but it was probably staged with a stuffed coyote. I have seen reports of boas caught in the everglades..but the number of reports our so small that there may not even be a breeding population and maybe just escapees and releases.
http://www.miamiherald.com/news/local/environment/article56857213.html
http://www.miamiherald.com/news/local/environment/article56857213.html