Consider the following markdown:
`a b `c
Note that there are two trailing spaces in the first and second lines. In the editing preview, this looks like this:
In actual posts, it looks like this:
I don't actually know which of these is "supposed" to be correct (according to a spec for markdown or something, if such a thing exists).
Note also that this bug is a reduced form of an actual bug experienced by a user on Japanese.SE (see this revision history), not a bizarre edge case thing I have deliberately contrived for my own amusement.