I feel the article itself is helpful, and it's good to see any newspaper acknowledging that such issues can be difficult, and sometimes errors are made.
The first comment left following the article was from @riseabove88. It read as follows:
the relationship between Assange and the Guardian and the NYT had foundered
Probably because David Leigh published the password to the redacted documents in that terrible book you were so keen to publish. Regardless if you thought it was a temporary password it still showed the habits to which Wikileaks passwords were set.
Now you've gone and spoilt it. This article seemed to be a genuine attempt to clear up one of the disputed areas between the Guardian and supporters of Julian Assange, giving hope that you might be moving to a slightly less negative stance; and then your moderators get involved.
The first comment on this article was a perfectly reasonable one by @riseabove88, which simply stated that the relationship between the Guardian and Assange was affected by David Leigh publishing the password to the widely available encrypted file in his book.
I've read the comment in Google's cache, and also read your Community Standards which describe what is acceptable or not. There are 10 points in them, which are all reasonable. Only one of these could possibly apply to this particular comment.
"We acknowledge criticism of the articles we publish, but will not allow persistent misrepresentation of the Guardian and our journalists to be published on our website. "
There was no misrepresentation in the comment, though sadly I don't feel I can add it here in full as that would give you an automatic reason to delete this one.
The deleted comment did however use the adjective 'terrible' to describe the book. Are you really as thin-skinned as all that?
Sadly, it only lasted about 10 minutes, and has disappeared without even a "This comment was removed..." note.
At a guess, being a comment moderator on the Guardian isn't the most fulfilling of jobs. I've asked them to explain their policy here.