The pine seeds I collected this year have done the same thing to me. They had no weight and some turned to dust like some of your buddha belly seeds. I soaked them overnight ... changing the warm water a couple of times .. and most of them sank so I put some in damp paper towels and they germinated. Some of the ones you cracked open look like they have healthy embryos. Try it before you throw them out.

Well I planted all 16 left over, its now been 5 days, I dug up a few today, and no sign of life yet. Not even root tips. So I am giving them 1 more week for ANY of them to germinate....after that, they go to the back of the garden and if anything EVER grows, ill be shocked. But I wont be 'fussing' over them, trying to get them to sprout. They are in moist soilless mix, so if they need moisture,they are in moist soil and full sun for heat. Now I wait.

The 1 seed in the pic. that looks like it has some 'meat' to the germ, is actually dry to, it split into a lot of pieces, that was just 1 part of the seed. The rest of it was all dust.