He should have known what to expect from Nolan, he's is probably one of the best paid chief of police in the UK and should have been much more savvy.
I agree with what your saying but my problem with delving into collusion, which undoubtedly was wide spread is that these investigations seem incredibly one sided. There seems very little will to investigate Garda collusion, to investigate and prosecute ANY IRA atrocity, Kingsmill, La Mon (which seems to be some collusion going on there too) to name 2 or any mainland attack. With regards to the Garda, no one is going to tell me that IRA men passed back and forth across the boarder and the Irish Police were not aware of it? Again how far did the collusion go, was it a handful of individuals or did it go further.
Even after a republican "missionary" last week publically stated on TV he wished he could have murdered more, no action will be taken in my opinion. I'm all for moving on, heeling, making bridges etc but it works both ways.