I don't grasp the emboldened sentence. Pls see the question in title.
How does investigating "whether there was a risk of a breach by the receiving state" differ from "whether such a risk actually existed"?
Colin Faragher. Public Law Concentrate (1 ed 2019). p 178. I skip to 3rd case.
The ‘outcomes is all’ approach
When applying the normal principles of administrative law, judges hearing applications for judicial review usually look at the decision-making process rather than the merits of the decision. This is not the correct approach when the challenge is based on an alleged infringement of a Convention right under the Human Rights Act 1998. In accordance with Strasbourg jurisprudence, the court is concerned with whether the claimant’s Convention rights have been infringed, not with whether the public authority has properly taken them into account. What is important is the practical outcome of the decision not the quality of the decision-making process itself. This means, for instance, that where a public authority measure is challenged by way of judicial review under the Human Rights Act 1998 for being disproportionate, it is sufficient for the authority to show that it had proportionate outcomes rather than that its proportionality was addressed during the decision-making process.
This was determined by the House of Lords in three cases.
The third case was R (on the application of Nasseri) v Secretary of State for the Home Department (2010). The appellant asylum seeker (N) appealed against a decision that his
removal to Greece did not breach Art 3 ECHR, and a decision to discharge a declaration of incompatibility. The claimant was an Afghan national who had entered the UK illegally after the rejection of his claim for asylum in Greece. The Secretary of State decided to remove the claimant to Greece. The claimant sought judicial review of the Secretary of State’s decision on the grounds that his removal would be contrary to Art 3 ECHR, as the Greek authorities were likely to send him back to Afghanistan where he would be ill-treated.
The House of Lords dismissed the appeal. The judge at first instance had been wrong to find that Art 3 created a procedural obligation to investigate whether there was a risk of a breach by the receiving state, independently of whether such a risk actually existed. The House of Lords decided that it is understandable that a judge hearing an application for judicial review might think that he is undertaking a review of the decision-making process, rather than the merits of the decision, in accordance with normal principles of administrative law. However, that is not the correct approach when the challenge is based upon an alleged infringement of a Convention right. The focus should be upon whether the individual’s Convention rights have in fact been violated.