 Their cause of death could not be determined definitively, but Dutch authorities working with forensic and search-rescue investigators thought it likely the students had accidentally fallen from a cliff after becoming lost.The circumstances and aftermath of their disappearance have resulted in much speculation about the cause of death, including the death of Leonardo Arturo Gonzalez Mastinu, the taxi driver who bought Kris and Lisanne to the Pianista trail on the morning of April 1st.Foul play could not be entirely ruled out and Panamanian officials came under fire for allegedly mishandling the disappearance and aftermath.