I discussed retrieval with Mendrum one time. The context was bones and what would be the priority for furnishing him proof of existence. He suggested if possible to leave it in the ground. Cover and mark it then call him in. This has advantages and disadvantages depending on who owns the land where it is found. If it is federal land it is a problem. The people that found the T Rex Sue on Federal land ended up gong to prison for two years for violation of federal laws. Leaving it in place allows strata dating and context as to where the bones were found. Clean, probably least likely to get you in legal trouble, but risky in that you could loose the location and the bones to authorities. If you decide to collect the bones the skull is highest priority. Next would be hands and arm. Femur is next then feet. Document the bones in the ground and remove everything if you can. Body parts would be in the same order if you find a body and cannot bring everything out.
Calling in Meldrum might be a problem if the location is not Idaho. He has standing there being associated with Idaho State University and probably knows who to talk to in dealing with authorities. Outside of Idaho he has no standing other than academic credentials. He may know who to call in Washington or Oregon and bring them in. But my opinion is that calling in someone in a University from the finding State might be a great advantage in dealing with authorities. Otherwise it is very likely when word of the finding gets out, the bones or body will be taken away from some lay person finder, who in the opinion of the state or federal authorities has no right to possess the bones or body. In the best of cases, the academics will give you finders credit. In the worst of cases, you will end up in prison for violation of antiquities or NA object or body possession.
I put out feelers and have found a Washington University PHD level biologist who might be a good person if I can get him to believe what I have found. I was able to establish email contact and actually have a conversation with him. He would be my starting point for a contact in my State of Washington. It might take a photograph of a bone to interest an academic.
Anyway my point is that if you are in the hunt for body or bones, you best grease the skids and have contacts in mind to call should you be successful. Finding something first without a contact could be a race with a rotting body. Smedja comes to mind when I think about these issues.