Seriously doubt that any reef-side hotel on Ambergris Caye has ever hosted "a few crocs" at the beach.
I our 12 years at the beach we have run across just one croc near the beach. It had fallen into a well that we had created to mix cement - the croc was maybe 7 feet long and it was rescued with with a LOT of caution.
Possibly the photo you saw was taken in lagoon behind Journey's End? Some rooms in that resort face the lagoon----- ? OR could be a fake photo.
The lagoons are croc habitat. On rare occasions, and in areas where lagoons are close to the eastern beach-shore, a croc will wander out to the beach - this occurrance is so rare that you need loose no sleep over it.