It seems like a bug to me.
If you look at the source of that revisionsource of that revision, you will notice that the poster used:
> * Example
Which normally produces the following output:
- Example
The default viewer handles this correctly, but the viewer for the revisions is probably a bit different and can't handle this kind of markdown.
This is a supported feature of markdown, however in their examples they show it being done with only a single space (rather than 4):
> * Example
... which produces the same HTML:
- Example
I will modify this post in 5 minutes modified to see if the same problem occurs here.
Nope, I wasn't able to reproduce it with this post.
- Test
Test
- Test
