I´m Sorry but you are worn Camilo:
Actually my point of view is the right one. Take a look of the following:
When Infante Jaime rennounced to his right to the throne of Spain, he did not resigned to the inherent position as apparent heir of head of the House of Bourbon; as Warren stated in this thread many times, one thing is to be the King and other is to be the Head of the House.
King Juan Carlos, actually, did not inherit the Crown of Spain from his grandfather Alfonso XIII. Juan Carlos I was "appointed" as King by Francisco Franco who was the absolute ruler of Spain who happened to be monarchist. Franco could have appointed any Bourbon he wanted to be the King of Spain as Franco's power in Spain was more absolute than any other ruler of his time.
When the French Bourbons took over the Kingdom of Spain many branches where created in Spain's Italian possessions and descendants of King Phillipe V of Spain became rulers; thus cadet branches of the Bourbon House where created. Then, we have the Bourbon-Parma, the Bourbon-Two Sicilies, etc.
The first Bourbon who bercame King was Henry of Bourbon, King of France, who reigned as Henry IV. After this King, the Head of the House was always the King of France (exception made of the Buonapartes and Louis Philippe I Orleans - a minor branch of the Bourbon House) until the death of Charles X of France.
The line of Bourbon Kings in France is the following:
Henry IV -> Louis XIII-> Louis XIV -> Louis XV -> Louis XVI - > Louis XVII -> Louis XVIII -> Charles X
Following the death of the Henry Count of Chambord (grandson of French King Charles X) the masculine legitimate male descendants of Louis XV became extinct. Therefore you have to find the elder masculine legitimate descendant of Louis XIV to find the head of the house, which leads you to the Spanish Bourbons.
Through Philippe V King of Spain (legitimate grandson of Louis XIV) the masculine legitimate line goes directly from Louis XIV to Luis Alfonso de Bourbon, whose grandfather, Infante Jaime of Bourbon was older than his brother Infante Juan (King Juan Carlos' father).
The head of the House of Bourbon passed from Alfonso XIII to Infante Jaime to HRH Alfonso Bourbon to HRH Luis Alfonso of Bourbon (who is a dual citizen of France and Spain).
The Orleans descend in masculine legitimate line from Louis XIII; they also descend from Louis XIV through his illegitimate daughters with his mistress Madame de Montespan, therefore the Spanish Bourbons have a better right to be the Head of the House than the French Bourbon-Orleans.