lots of times that happens to me, and it's because of some fine bits of flint that fall out of the end of my lighter and into the bowl... it's too small to see, dust really, but when the fire hits it - it sparks. freaks me out because I think it's a seed that might blow up sending hot embers into my eye.
I know what you're talking about, that happens to me too, but this was definitely something else. The flint-sparks happen when I just flick the lighter over the bowl without pressing the gas button.

This crackling was from the weed itself as it burned, like every little bit that the ember spread to popped.

The other bizarre thing about it that I only just realized is that its only a single bud from the bag I bought that does this. I smoked a bit from that bud and it cracked and sparkled, then smoke a bit from a different one and it was totally normal.

I hope it wasn't "flushed" or whatever all that is incorrectly and I'm gonna be poisoned or something.

And whenever I sip coffee after smoking it tastes exactly like tomatoes.