I'd say that it's likely that the 1864 reference (Forney) or some source of his somehow got confused by some wording somewhere pertaining to the pre-1834 light pink to rose Bourbon or China 'Général Dubourg', with this result. Anything's possible, however: Since there's no other mention by anyone of the Dubourg origination, and the statement comes about 40 years after the rose's introduction, perhaps it's better to relegate Dubourg to a footnote, as in "Forty years after the rose's introduction, author Forney stated, without giving a source, that it originated with Général Dubourg, a statement which we record here without accepting or denying."; There was a Dubourg in Vaucresson at the time who did indeed involve himself with Chinas etc.; but I've never associated him with the military/political figure Général Dubourg, and Forney explicitly states that it's the General from whom it came. As we see from Desportes, the Dubourg of Vaucresson seems to have been able to offer his Chinas and other roses without the intervention of Laffay, as we see from Desportes.