Why have you taken just that one sentence out of context?
The full context is :-
Quote
My professional opinion as regards to the EVRD's alert indications is that it is suggestive that this is 'cadaver scent' contaminant. This does not however suggest a motive or suspect as cross contamination could be as a result of a number of given scenarios and in any event no evidential or intelligence reliability can be made from these alerts unless they can be confirmed with corroborating evidence.
unquote
IMO the sentence should be read in context - to ensure that a different 'meaning ' to the one intended by M.Grime in that part of his statement - will not be conveyed to the reader.
Grime trained and worked with his dogs and was very sure about their abilities;
The dogs' passive CSI alert provides an indication as per their training and does not vary. They only give an alert when they are 'positive' that the target of the odour is present and immediately accessible.....EVRD does not make a distinction; he responds with a certain behaviour for which he was trained when he recognizes an odour. He does not identify the reasons for the presence of the odour nor does he identify suspects......The dogs do not get confused. They transmit a behavioural response inspired by the recognition of the odour for which they were trained..It also should be taken into account that the procedures for forensic testing are still less discriminating than the system of dogs' smell. ....
http://www.mccannpjfiles.co.uk/PJ/MARTIN_GRIMES_RIGATORY.htmWhen he gives his professional opinion, therefore, it is based on the above belief in his dogs. When it comes to the legal position he reminds that there is a burden of proof which must be met; dog alerts or their handler's opinion won't stand up in court, forensics are required.
The question to be addressed is whether to dismiss the expert's opinion because the forensic team didn't get sufficient evidence for a court case. If investigators dismiss alerts completely which can't be verified they would look silly if the dogs were later proved correct. if they rely on the alerts completely they would again look silly if another scenario is proved correct. The sensible approach seems to be to keep the alerts in mind during the investigation as they suggest one possible scenario.