The state of falling off climbable blocks is lost upon reloading the world, causing incorrect death messages

The Bug:

The state of falling off climbable blocks is lost upon reloading the world, causing incorrect death messages.

Steps to Reproduce:

1. Build the setup as shown in the provided attachment around fifty blocks up from the ground. setup.png
2. Summon a wolf beside the slime block, tame it, and make it sit.
3. Press the button and when the wolf die, observe how the death message is "Wolf fell off a ladder".
4. Repeat step 2 and press the button.
5. Before the wolf hits the ground, quickly reload into the world and observe the death message that's displayed in chat when the wolf dies.

Observed Behavior:

The state of falling off climbable blocks is lost upon reloading the world, causing incorrect death messages.

Expected Behavior:

The state of falling off climbable blocks would be kept upon reloading the world, causing correct death messages.