The Elytra can currently kill players when they fall from a height that they shouldn't take fall damage from...

How To Replicate:

Step 1: Using an elytra, fly into a wall (which gives you the bug enabling you to walk through gaps which you otherwise shouldn't)

Step 2: In the end, go to any place that has a Shulker and get hit so you get the levitation effect, once floated into a block, you will see nothing but the inside of a given block.

Step 3: Once the leviation effect wears off, you will fall (Likely from 4 blocks or so) and despite not being a height that you would take fall damage from, you will die instantly upon touching the ground.

I will update with a video when possible...