Summary retirement of Nigerian officers

In 2016 Nigeria involuntarily retired 38 senior officers for cause (partisanship and involvement in a procurement scandal). They have appealed the action to the country's president; some have gone to court. The question is whether they were afforded due process in these adverse actions. The officers appear to claim that they are entitled to a trial at which the evidence can be examined. This opinion piece in Vanguard is unclear about what process they did get -- was it simply notice-and-comment decision making, or even less? Excerpt:

Enquiries revealed that Major Generals SD Aliyu, MY Ibrahim, FO Alli and Wiwa appeared before the presidential arms panel, while Major General Atewe is in court with the EFCC over embezzled funds. Others who appeared before the arms panel included Brigadier Generals Onoyiveta, Onibasa, Mormoni-Bashir and Abdulsalam. They were all cleared and not indicted, if indicted they were entitled to appear before a court martial for trial. The panel does not have conclusory powers to assign guilt under military law. It is a fact finding body preparatory to a court martial. 

The following retired officers were not indicted, queried, charged or convicted via any court martials, they include Major Generals Ijioma, Ejemai, Ilo and Ude. Others are Brigadier Generals Bello, Koko Essien, Lawson, Bright Fibionuma and Agachi. The list also includes Colonels Ekpenyong, Kayode, DR Hassan, Suleiman, Nwankwo, Minimah and Ukoha. Others not queried or even charged are Lieutenant Colonels AS Mohammed, A Mohammed, Dazang, Arigbe, Adimoha, Baba-Ochamkpa, Egemole, Amadi, Oladuntoye, Enemchukwu and Major Williams. That is 27 senior officers summarily retired without being accused, charged or found guilty of committing an offence. 

Is this how things are currently done in [Tukur Yusuf] Buratai’s Army? What manner of impunity is this? I thought we had a professional army where the arbitrariness of yesteryears was consigned to the dustbin of history! Doesn’t a man deserve to know his offence, if indeed he committed any? This is why the retirements don’t make sense and don’t add up.