Late during their stay on the island, the skirt of Joan Collins' yellow dress is show to have been torn off in the front at about mid-thigh level, showing off her legs, yet when the rescue boat arrives the dress is not torn, but rather is in near pristine condition.
The Bikini worn by Joan Collins' character Sadie, supposedly made on the island out of a piece of cloth taken from a sailor, is obviously professionally made and fitted, not something that could be made without any equipment on an island.