The "cover up" title invites comparison with Bloody Sunday.

First distinction. Those contributors who fell over themselves to express their outrage over BS, are conspicuous by their absence here.
Is that because of the nationality of the perpetrators?

Next. One cover up prevented the prosecution of British soldiers.
(Shame. Outrage.)
The other cover up prevented the prosecution of an IRA mass murderer.
(....)

I suggest that both cover ups were intended to avoid exacerbating the violence that could so easily have led to civil war. Nearly 500 killings that year.
You can argue that was misguided, but the motive was good