The background to the Damascus Affair (ie, the 1840 blood libel against Jews that became famous around the world) is or should be well known. If not, click the link.
What is most interesting is that in reaction the Times of London printed a translation of virtually the entire Haggadah on page 3 (August 17, 1840 edition) titled "Celebration of the Passover by the Jews."
It begins "A correspondent has furnished the annexed very minute account of this ceremony, which will be exceedingly curious in itself to most of our readers, and has at the same time an evident bearing on the Damascus case. It repels strongly the barbarous notion that human blood, or blood of any kind, is essential to its celebration:-- (click below to enlarge)
It must be noted that shefoch chamoscha is not mentioned (nor Chad Gadya, the other songs at the end or the declaration of Lshana Habaah be-Yerushalayim). One cannot help but get the impression that it was not mentioned not because the editors of the Times were duped by whomever prepared this translation and account. It was a time of almost comical erudition about all sorts of obscure topics in the mainstream press.
As Simon Winchester writes of a slightly later period in "The Meaning of Everything: the Story of the Oxford English Dictionary," "[F]or very many they were also cultured and learned times besides. . . . It is perhaps worth recalling just how very well educated people were in those days - or at least to recall how very well educated the educated clases were. . . . [p]eople, or people of a certain kind in the Britain of the day, were quite simply possessed of much time and much learning, and in far greater abundance than many like people possess it today. Items from the newspapers of the time hint at the almost incidental, quite casual cleverness of the cleverest of the reading public. An illustration of the kind of things appears that day in the 'Telegrams in Brief' section of The Times, in which it reports, without explanation or adornment, that:
Further hostilities are reported between the Zaranik tribe and the forces of the Zaidi Imam Yahya of Sana'. The Zaranik attacked a Zaidi detachment at Mansuria, near Hodeida, and have been plundering caravans trading with Sana'.
No further details are offered to suggest where all this fighting was (Yemen, one imagines), nor the identities of the parties to the feud. The newspaper's editor presumes that readers, quite simply, had sufficient education to know.
In short, I suspect that the reason why the last hour of the seder is summed up in a paragraph mentioning birchas ha-mazon, but not what can legitimately be seen as a dark moment of the seder (shfoch chamoscha), or the messianic hopes of the Jews (leshana habaah be-Yerushalayim) was because the editor thought it best not to mention it, fearing that such moments would distract from the thesis the paper was trying to present: that what actually happens and what is actualy said by a Pesach seder "repels strongly the barbarous notion that human blood, or blood of any kind, is essential to its celebration."
Further reading: 1841 English translation of Effés Dammim: A Series of Conversations at Jerusalem Between a Patriarch of the Greek Church and a Chief Rabbi of the Jews, Concerning the Malicious Charge against the Jews of using Christian Blood by the maskil Rival (Yitzchak Baer Levinsohn), author of Teudah Be-yisrael. Appended to this particular book is a must-read: extracts from "Reuchlin's defense of the Talmud," pp. 201-208.