Partly intangible falling platforms in ACZ

[Majro]

After the first checkpoint in ACZ, on the leftmost path, the one with Speed Shoes and a Whirlwind Shield right after, you can go right through the bottom halves of the two falling platforms. The top halves are solid.
No other falling platforms in the level seem to act like this.

I've been able to reproduce this in 2.0, so it looks like it's been there for a while.

 

[ManimiFire]

I think it's because of the linedef type: "Linedef type 140, Intangible from Bottom, Opaque."

 

[Monster Iestyn]

To be fair, since they're crumbling FOFs that are opaque, the only linedef types they could be if they were meant to be intangible from below is 172 or 173.

If they aren't meant to be intangible from below, that's a bug.