Well, that is true. I can imagine the reporter thinking to himself, "I don't remember him saying that, I'll check with some of the other people that were there to see if they remember it." Which is apparantly what he did.
This quote seems to say that the reporter remembers something specific that was misquoted:
A lot of articles have been written about this. You'd think that some of the reporters would have contacted the reporters that were there to clear this up or possibly Clark himself (and maybe they did try). I don't know, maybe it is just easier for them to sit down and start writing their, "If this is true, how does it affect the primary or the general election" story than to actually look into it.
(and I checked out Drudge this morning, three links to the Sun that you mentioned above about the parents. One of them at least ends with "Both Kerry and Alex have denied any affair." It is treated like an afterthought!)