Nick, do you know for a fact that they stripped all the needles off? They may have been one of the spineless cultivars. of course, that book could easily be wrong. either which way they are tasty and I ate a ton of them when I was in Costa Rica as well.
I did a little research and I think the palm that OutonaLimb is referring to is actually a different one, Astrocaryum standleyanum. This is one viscious palm! of course we got one palm here at the arboretum (name escapes me) with spines all up and down the trunk that are almost a foot long. One girl had to go to the hospital to get a 2 inch chunk of spine dug out of her arm. And don't even get me started on the rattan palms. I fell into one about two weeks ago and I'm still digging little spine tips out of my arm!