Leval`s division lost 17 guns at Talavera, which were handed over to Cuesta`s army after the battle. King Joseph, Marshal Jourdan, Generals Sebastiani and Senarmont were all involved in a plot to cover up this loss from N. N, however, found out the truth by reading English newspapers and vented lots of spleen on the plotters. Luckily for them, these guns - and several others - were retaken by Soult at Arzobispo from Cuesta on 8 August 1809, so the conspirators closed ranks and maintained that no guns were lost in the battle of Talavera.
Did N ever find out the truth? I imagine Soult would have been happy to stick it to Joseph.