That's interesting, it shows up perfectly for me in the comment (latest Firefox, Ubuntu 12.04).
Not on the iPad :(
Yes, I see the problem -- I assumed that other browsers were using a monospace font for the HN monospace-markup sections. This isn't always the case. Even my rendering in Google Chrome on Linux isn't perfect.
Your browser's monospace font isn't monospace. You should choose a different one.
If the monospace font doesn't support those characters, maybe the browser fell back to a non-monospace font.
No, if you look at the ASCII version posted above, it's distorted too (the big parenthesis are wrong, for example).