Point of clarification required; is fried pecan pie a pie made from fried pecans, or a pie made from pecans that is subsequently fried while in pie format?
If your neighbor says they’re edible, and presumably eats some of them himself, I wouldn’t worry about it.
And have you considered the possibility that your mother did know what they were, and just told you they were yucky so she could have more for herself? Coincidentally, this is exactly what several of my aunts told me about pecan pie (the merely baked variety, however).
Man, if only I had a nickel for every time I was up for 40 hours driking beer with a neighbor while eating strange fruit and pecan pies, running into poo and barfing throughout the neighborhood.
“Ahhh… but… a little research suggests that some palm fruits contain calcium oxalate; this can be harmful - they can cause irritation of the mouth and digestive tract, and in higher doses, poisoning.”
As much oxalate as spinach (0.75% by weight)???
Regarding “sago palms.”
According to Wikipedia, the Sago Palm, “Metroxylon sagu,” is an important food in some Pacific islands. The cydad (not a palm) sometimes referred to as a “sago palm” is poisonous, although it can be eaten after extensive, careful processing.