Probably my Favorite Eastwood Movie
I first saw this as a child and enjoyed it, but did not understand all the nuances of what was happening. This may have been in part because I watched an edited version on television. After seeing it again recently, I appreciate it all the more for the twisted things that I missed before. I think there were great performances by all, even Pamelyn Ferdin, whose voice usually annoys and distracts me.
My interpretation of the ending is that it is supposed to be ambiguous in the sense that only Amy knew for sure if the mushrooms were poisonous or not. Martha encouraged Amy to gather mushrooms especially for McBurney just after he killed her pet turtle yet I don't think Martha knew for sure whether they were poisonous; she didn't want any of the girls to eat any in case they were. Poisonous or not, it would seem to me that he sort of "died of fright" because even if they were poisonous, he should have been able to get himself to throw them up since he had just consumed them, but instead he panicked and flailed around uselessly. People can say it's a dumb ending and unrealistic, but it's not impossible, for all we know he could have had a weak heart, and he had been through a huge strain (having his leg amputated).