Lack of premortem hemorrhaging on cattle pretty definitively rules out wolf attack. Wolves kill large prey by crushing muscle with strong jaws and relatively dull teeth; actual wolf kills without feeding are often missed due to the absence of punctures in the hide, but when skinned the extensive muscle trauma is very apparent. (The included photo is 19 elk killed on a Wyoming feed ground. Note that although all 19 were killed by wolves and dragged to the location on snow with snowmobiles, there is almost no bleeding.)
No other wild large carnivore in the PNW kills this way, and as long as the carcass is fresh a wolf/not wolf determination can be made even without determining the "other" causes.
If there are good quality photographs of the skinned carcasses - which there certainly should be - experienced depredation investigators would be able to determine whether or not it is a wolf kill, so this is not necessarily an ODFW/Sheriff impasse. My guess is that government employees at either state or county level, in a state that has had very little experience with wolf depredation, probably aren't very experienced and are both learning on the job. Many biologists have relatively little experience with conducting necropsies and investigating a suspected wolf kill is likely a first time experience - they followed the instructions, but how confident are they in the conclusions? I do find the sheriff's adamant certitude more political than professional.