To this day I am so confused as to why Snow White claimed in the Pilot that Regina "poisoned an apple because she thought [Snow] was prettier than her." It didn't fit into the story whatsoever, and though I loved the show, I always wished they stayed a bit truer to the original Snow White fairytale. I would have loved if they did something similar to the Land of Stories Evil Queen.
It was the pilot episode, so I doubt that the writers had planned that far ahead.
Alternatively, if they had planned out the Snow/Regina feud, then they wouldn't want to spoil it in the very first episode. You can imagine how much mystery and suspense would be taken out of Season 1 if Snow White flat out revealed what happened in the very first episode.
I liked the twist but I've always thought Regina would blame Cora more than Snow.
I understand the pilot aspect... I'm just huge on canonical information and hate retconned material in any sense. I enjoyed the twist, but I wish the themes of vanity and narcissism the original take had were more prominent.
I like to think that Snow lied to Charming because she felt guilty and maybe she feared that if Charming knew the truth he may not trust Snow anymore and even leave her. Eventually Snow revealed everything to Charming (David says so in Season 2).