Good catch. Was the hide damaged or destroyed?
I accidentally did that too once except I lit the fire myself, and my hide wasn't damaged at all. I think while it's tanning it might not count as being actually there for determining whether it burns or not (which itself could be a bug / a not featured thing).
When it happened to me though it was a few versions ago so that's why I ask if your hide is okay once the fire is out, though the answer might be different if it finishes tanning before the fire ends or if it's still in the process then.