Player dies after jumping into the End's exit portal

Recently I went into the End to collect some endstone and mess around with endermen. It wasn't my first time into the End as I had built various things there. I climbed to the top of the black spire nearest to the exit portal and I jumped in; the credits rolled and I skipped them. When I came back to my spawnpoint (bed) I had died! None of my items were near the bed when I respawned again; so I went back into the end to sort things out, when I got there I could only find some of my items (This was well within the despawn time.) From what I understand the fall damage might've transfered to the overworld, so when I touched the ground the game must have thought I had fallen.