Having to mark things read is a bit of a pain, but not that big a deal.
What's most annoying about it is that he should know better than to think that he can disappear from here by doing that. He's a very bright guy - he should know that there are a variety of web archives; the [link|http://web.archive.org/web/*/z.iwethey.org/*|Wayback Machine] is just the most famous. He's got a history on Usenet too.
He also should have checked with admin before trying to wipe things.
Yes, the apology is good, but didn't really address the issue of why he felt compelled to do it the way he did.
I'm genuinely sorry that he felt it necessary. He should take comfort in the fact that billions of pages have comments from millions of people who have said more than they should at one time or another. We're all going to be around in spite of it. ;-)
Cheers,
Scott.