Pakistan is among the world's leaders in the improper exercise of military personal jurisdiction.
Human rights jurisprudence strongly disfavors the trial of civilians by military courts.
The use of military courts to try retirees has been repeatedly condemned by the Inter-American Court of Human Rights. The constitutionality of such trials in the United States is currently in litigation. [Full disclosure: the Editor is counsel in one of the pending American retiree cases.]
P.S. Dawn reports here that the civilian who was among those convicted had been associated with Amnesty International and had investigated enforced disappearances. As Dawn noted in an earlier article, the Peshawar High Court had declined in January to block his court-martial in advance. See Khattak v. Government of Pakistan, Writ Pet. No. 4271-P of 2020, 2021 PLD Pesh 135 (Pesh. High Ct. Jan. 28, 2021). Watch for review of the court-martial under the Army Act and in the civilian courts.