Суть термина collusion поясняется в статье, с которой можно ознакомиться по ссылке:
http://www.theguardian.com/uk/2008/oct/24/ukcrime-police1

Приведу начало материала:

Firearms officers told to stop colluding over statements
Police chiefs decided yesterday to end the controversial practice of firearms officers writing up their statements together. The practice had been criticised by the high court as an institutionalised "opportunity for collusion".
The Association of Chief Police Officers accepted the criticism which came after a case bought by the family of the barrister, Mark Saunders, who was shot dead by the Metropolitan police.
A senior source told the Guardian: "Officers will not be able to confer about the crucial points. It's obvious that in the immediate aftermath people will talk to one another. But when they sit down to write an account, they will not be able to do so together. It's just about openness, if you have talked to a colleague about the case, that should be recorded."

Под statements имеются в виду отчеты, которые составляются, например, полицейскими.

Иными словами:

Независимая комиссия по проведению расследований также разработала для полиции и других служб охраны правопорядка рекомендации по некоторым вопросам (с упором на прекращение практики согласования и совместного составления отчетов…

Имхо, как и обычно.