Right at the start of the film, we find out what happened to the female astronaut, Stewart, whose stasis capsule malfunctioned and caused her to wither and age into a horribly desiccated corpse, which is actually shown on screen with a creepily realistic mannequin. Then there's the question as to whether she simply slept through her aging to death or that Stewart was somehow conscious and aware through it all.
The hunt sequence; all of a sudden, a peaceful frolic in the wilderness turns into a nightmare as unseen stalkers begin blowing horns and shooting at our heroes, who can only run for their lives as the native humans scatter and die all around them.
Followed by the climactic reveal; the hunters on horseback are Killer Gorillas with rifles, complete with scenes of them posing with their kills like human hunters.
Taylor learns in the "zoo" that the apes plan to geld him, which he only does because they still think he's just a dumb, unthinking animal.
During Taylor's flight from the zoo, he stumbles across a science museum... where he finds his former African-American colleague (who was shot during the hunting scene) has been skinned, stuffed and mounted for display. It's implied to be because he's the only dark-skinned human the Apes have ever seen, as all the other humans shown in the movie are just caucasians with the occasional tan, making him a very unique trophy.
And his other colleague in a fully-lobotomized stupor.
The whole idea of the trial, where Taylor must fight to somehow convince the apes to let him live even as they accuse him of heresy for something he has no knowledge of. During the trial, he meets the last of his crew - now a lobotomized vegetable - and is told that this is the fate that awaits him if he doesn't confess to be something he isn't.
Yes, The Reveal has long since become a familiar version of It Was His Sled, referenced and parodied to death, but remains surprisingly impactful - Taylor and his crew didn't land on some bizarre upside-down alien planet (which did happen in the original novel), it was Earth All Along, with the Statue of Liberty in the Forbidden Zone being one of the few traces that human civilization ever existed at all.
