Of course Howie had to get in a dig in the last couple of sentences. Has to repeat the "but the story is true" line.
Translation:
Of course we know the documents are forgeries. That doesn't matter though because we're pushing an agenda and we're hoping you are all too incredibly stupid to understand that any allegation found in a forged document is worthless.
With reference to your "Of course Howie had to get in a dig in the last couple of sentences. Has to repeat the "but the story is true"
line." That is standard Washington Post policy, closing a story in such a fashion as to let the writer tell his/her customary liberal reader that the writer doesn't support any conservative position on any matter being written about.