Thanks for the info.

I ran this on a fairly old forum - one that came from the wwwthreads days.
And I got results for all of them. Modern versions have some checks built in to prevent some of this stuff. Like I believe in 6.3 or so - a check was added to recalculate the number of replies if it's inaccurate. And I know in 6.2.3 or so a check was added so that if the parent post was deleted while you were replying, it stops you from making the post.