Departure off the island at the last moment

>>> the helicopters were trashed and thrown in the ocean at the last moment so the enemy couldn't make use of the equipment

Actually the choppers were deep-sixed to make room on the carrier flight decks for helicopters still en route to have a place to land. The pilots of others had to make water landings near warships that had no flight decks. Besides, who would have been dumb enough to fly them back and return them to Charlie? Worst case scenario you're shot down trying to land. Best case scenario you're thanked and rewarded with five years in a rehabilitation prison camp.

The script is written from the usual Hollywood point of view that the guerrillas were the true good guys. Like the contemporaneous fawning New York Times headline of Castro, "The Robin Hood of the Caribbean". The commander is shown to be a reformer, idealistic, realistic, and generally quite civilized. Just the sort who within the year were stood up against a wall by Che and shot as a danger to the revolution.

The genuine idealist and reformer is the biggest enemy any communist state faces. But history shows they seldom figure it out in time. The Felix Dzerzhinskys and the Che Guevaras always blindside them with reality.