You can go through floor when burning boat on grass path

I went through a grass path when burning a boat

What I expected to happen was....

Me to be on the grass path when i got out

What actually happened was....

I went under the blocks when i got out

Steps to reproduce:
1. Go on a minecraft server(didn't work in my single player world)
2. Make some grass path next to some blocks
3. Get a boat on the path
4. Dig out an area under it
5. Place some wood next to the boat
6. Get in the boat and drive into the wood planks
7. Light the wood on fire

Additional notes:
sorry for the low quality video it was to big to fit normal quality