suffocation death results in falling out of world

On two occasions I have suffocated in wall and the end result was falling out of the world. Both deaths occurred in the overworld while playing vanilla survival, no cheats. The first time this happened, I suffocated in a tree at sea level, the second time this happened I suffocated from falling gravel blocks at y = 6. In both instances damage from suffocation occurred, right before death I was falling out of the world until death. All items and experience were lost. 

There were no redstone contraptions involved. No mods were involved.