We seem to have two threads going, here and the Operation Task debrief. A bit difficult to know which thread to post on as Op Task is part and parcel of the initial investigation.
Having now read the debrief, it confirms my impression of a chaotic situation.
On the one hand, the PJ were under-resourced (in every sense, including a lack of experience); the UK agencies could offer expertise and other resources, but in the enthusiasm, were perceived as an unwanted foreign "invasion" by the PJ with a pride issue (IMO), understandable to a certain extent, led by a coordinator, himself under investigation in the only other investigation of that nature...
There was no doubt frustration on both sides and, sadly, investigative opportunities were no doubt missed.
IMO, this debrief may well have been a background document for the later "scoping excercise", which eventually led to the UK review/investigation.