You can see dead/flagged comments via a setting, perhaps only exposed to users if their own score is high enough(?).

I've thought about making a site that publicly indexes and exposes all flagged and dead HN comments and stories.

Occasionally there are gems.

hnflagflyer.com

You should be able to turn on the "showdead" option in your user settings to see the text. But (like the other user) I'm not sure if there's a minimum karma amount for that toggle to show up.

I was referring to the API.