7 that the Inter-American Commission has autonomy and independence in the exercise of its mandate12 and, particularly, in the exercise of its functions in relation to processing individual petitions, established by Articles 44 to 51 of the Convention.13 Nevertheless, the Court has the authority to control the legality of the Commission’s actions as regards the processing of matters that the Court itself is examining.14 The Court has maintained the opinion that the American Convention grants it full jurisdiction over all matters relating to a case submitted to its consideration, including those concerning the procedural assumptions on which the possibility of it exercising its competence are founded.15 This does not necessarily entail reviewing the proceedings before the Commission, except in exceptional cases where a grave error exists that violates the right to defense of the parties.16 23. Also, the party who states that a grave error which affected the right to defense has occurred owing to an action by the Commission during the proceedings before the latter must prove this injustice.17 Hence, a complaint or difference of opinion with regard to the Inter-American Commission’s actions is insufficient. 24. The Court observes that the case file does not support the State’s argument that the alleged failure to comply with Article 28 was not considered during the proceedings before the Inter-American Commission and had only been included in the application after the State had made a comment relating to compliance with the reparations required in Report on Merits No. 14/07. During its proceedings, the Commission examined the facts of the case in light of Article 28 of the American Convention, concluding in the said Report on Merits that the State had failed to comply with the obligations deriving from the so-called “federal clause” and, consequently, alleged the supposed failure to comply with this norm in the application it filed before the Court. 25. The Court finds that the inclusion in the application of the supposed failure to comply with Article 28 of the American Convention, which appeared in the Commission’s Report on Merits No. 14/07, is not contrary to the relevant provisions of the American Convention and the Commission’s Rules of Procedure. Moreover, during the processing of the case before the Court, the State had the opportunity to submit its arguments for the defense on this aspect of the application. Furthermore, it has not proved that its right to defense was impaired owing to the said action of the Commission. Thus, the Court finds that there are no elements that would justify modifying what has been decided by the Inter-American Commission in this case. 12 Cf. Control of the Legality of the Exercise of the Attributions of the Inter-American Commission on Human Rights (Arts. 41 and 44 to 51 of the American Convention on Human Rights). Advisory Opinion OC-19/05 of November 28, 2005. Series A No. 19, first operative paragraph, and Case of Castañeda Gutman, supra note 9, para. 40. 13 Cf. Control of the Legality of the Exercise of the Attributions of the Inter-American Commission on Human Rights (Arts. 41 and 44 to 52 of the American Convention on Human Rights), supra note 10, Second operative paragraph, and Case of Castañeda Gutman, supra note 9, para. 40. 14 Cf. Control of the Legality of the Exercise of the Attributions of the Inter-American Commission on Human Rights (Arts. 41 and 44 to 51 of the American Convention on Human Rights), supra note 10, third operative paragraph, and Case of Castañeda Gutman, supra note 9, para. 40. 15 Cf. Case of Velásquez Rodríguez, Preliminary Objections. Judgment of June 26, 1987. Series C. No. 1, para. 29; Case of Castañeda Gutman, supra note 9, para. 40, and Bayarri v. Argentina. Preliminary objection, merits, reparations and costs. Judgment of October 30, 2008. Series C No. 187, para. 28. 16 Cf. Case of the Dismissed Congressional Employees (Aguado Alfaro et al.) v. Peru, Preliminary objections, merits, reparations and costs. Judgment of November 24, 2006. Series C. No. 158, para. 66; and Case of the Saramaka People v. Surname. Preliminary objections, merits, reparations and costs. Judgment of November 28, 2007. Series C No. 172, paras. 32 and 40, and Case of Castañeda Gutman, supra note 9, para. 40. 17 Cf. Case of the Dismissed Congressional Employees (Aguado Alfaro et al.), supra note 16, para. 66; and Case of the Saramaka People, supra note 16, para. 32, and Case of Castañeda Gutman, supra note 9, para. 42.