Human rights — Due process — Admissibility of author’s communication to Human Rights Committee — Consideration of merits — Right to humane treatment — Right to fair trial — Whether procedural irregularities resulting in unfair trial — Reliability of confession — Burden of proof — Whether delay in reviewing trial decision — Whether Sri Lanka violating Article 14 read together with Articles 2(3) and 7 of International Covenant on Civil and Political Rights, 1966 — Effective and appropriate remedy — International Covenant on Civil and Political Rights, 1966, Article 2(3)(a)