And here's the fundamental issue both with Ferryman's continued self promotion as some kind of expert on EVRD and Roger's questions in this thread.
Posters are forming opinions on Grime, his methods and the reliability of his dogs on the basis of reading his reports from the files added with other disparate reports from him and other EVRD handlers and attempting to form some definitive conclusions.
However without the technical, professional or academic knowledge you simply cannot attempt to fill in the gaps and draw the dots together to create a whole picture.
The information needed to make sense of it all and pull all his methods and the information together simply isn't there and other than him coming on the forum and answering any and all questions, whilst anyone can attempt to join the dots themselves, they do so at their peril because they simply do not have the expertise to pronounce authoritatively on him or the subject.