Slow justice in India (one in a series)

Okay, so last December the High Court in Chandigarh, P.B. Bajanthri, J., set aside a court-martial for vehicular homicide (rash and negligent driving) because the accused, a soldier with 23 years of service, was not informed of the consequences of pleading guilty. Singh v. Union of India, CWP 10501-2010 (O&M) (Punjab & Haryana High Ct. 2017). Fair enough. But consider the chronology:

June 2006, date of offense
June 13, 2006, case referred to the Army by a civilian magistrate
Mar. 30, 2008, general court-martial
Aug. 19, 2008, accused changes plea to guilty
Mar. 30, 2009, sentence adjudged
June 3, 2009, accused discharged from the Army
Feb. 10, 2010, sentence upheld by next higher authority
2010, High Court case filed
Dec. 20, 2017, High Court decision

Seems like a mighty long wait for a 10-page decision in a fairly simple case.

Query for readers in India: why wasn't this case in the Armed Forces Tribunal rather than the High Court?