Some important points on inconsistency and credibility in trafficking cases from David Lock QC, sitting as a deputy High Court judge:
The expert evidence in this case from Mr Steve Harvey, who has long experience in the police and in Europol in trafficking matters, is that he has never known a trafficking case where there were no inconsistencies in the account of events given by the victim. Inconsistencies may, of course, be evidence to suggest that a person is lying but in this context it is important decision makers recognise that there are many other potential explanations for inconsistencies.
In a case where a person has suffered substantial trauma from repeated beatings and other unspeakable behaviour at the hands of those who controlled him, the psychological consequences of those events may result in the applicant’s recollection of events being entirely incoherent and thus of no value at all in deciding what had happened to him or he may continue to be so fearful of those who were controlling him that he may deny there was any abuse, coercion or forced labour. This is expressly recognised in the Guidance. In such a case, the applicant may be lying or his account of events may have no value whatsoever but the evidence of the physical or psychological condition of the individual will nonetheless be more than sufficient evidence that the person was a victim of trafficking.
The case is R (TVN) v Secretary of State for the Home Department  EWHC 3019 (Admin).