Ralph's remembering Simon's words from the night of the dance is also extremely revealing--the only way Ralph could have known what Simon was saying is if he were part of the inside circle that killed Simon. It's the "painful admission" that he had been at the dance, made even more painful by the fact that he was an active participant.
Ralph reluctantly and awkwardly admits to remembering Simon's words. The group of Piggy, Sam, Eric and Ralph is moritfied, ashamed, and shocked at what took place at the pig roast on the beach where Simon was killed. They don't want to admit that they were with the other boys at the time. This makes Ralph's recollection of Simon's words both a show of practical bravery and a hint of guilt.
I agree with the two posts above, and I would add one more "Ralph is more perceptive than" example. Jack is the least likely of the four main characters to remember anything anyone else says, especially Piggy or Simon. The only reason he listens to Ralph is so he can use his words against him. Jack only cares about what is in front of him and would not see symbolism or importance in the dead parachutist. Given that, I would say that Ralph is more perceptive than Jack, which is why it is unlikely that Jack would remember anything like the dead parachutist.
I agree with #3. The novel clearly states if you look at it carefully that it is Ralph who in Chapter 10 recalls the words of Simon about the dead parachutist, which of course is significant because this chapter gives us another example of how Ralph is more perceptive than Piggy, though not as perceptive as Simon was. Ralph is clearly aware of the existence of a metaphorical kind of evil that is going to turn physical very shortly.
In Chapter 10 of Lord of the Flies by William Golding, it is Ralph who recalls what Simon has said of the dead parachutist:
Ralph remembered the ungainly figure on a parachute
"He said something about a dead man." He flushed painfully at this admission that he had been present at the dance. He made urging motions at the smoke and with his body. "Don't stop--go on up!"
Ralph urges the boys, Sam and Eric to replenish the fire as a signal, but also as light to protect them from the darkness. For, unlike Piggy who rationalizes, the unnerved Ralph recognizes that there is evil present, but he is not intuitive as Simon and cannot understand that the beast is within them.