Nether Portal Blocks break like normal blocks

I was testing out the new huge nether portal update, when I broke one of the
purple portal blocks. It played the sound of glass breaking and left a
random hole in the portal.

What I expected to happen was...:
It should have taken down all of the portal, like normal.

What actually happened was...:
It left random gaps.

Steps to Reproduce:
1. Make a large nether portal.
2. Light it
3. Break the portal blocks (not the obsidian!)
4. It will leave a gap