Yes. First of all, they got a search warrant in this case. It’s been sealed but it is believed to cover the search of the house. It could’ve covered the work site as well. We don’t know.
But with a search warrant there needs to be a showing of probable cause that evidence of a CRIME has been committed in the area to be searched.
And bringing in sonar and digging up an expensive concrete pad, that’s not going to happen without a search warrant. And certainly not at the insistence of a third party property owner. Citizens don’t get to direct law enforcement in their searches.
Second, only three days after she disappeared:
“Spezze declined to comment on whether Morphew’s husband is cooperating with authorities in the search for the woman or whether investigators believe foul play was involved.
‘This is an open criminal investigation,’ Spezze said during a brief interview.”
https://nypost.com/2020/05/13/colorado-woman-missing-after-going-on-mothers-day-bike-ride/
Of course they quickly softened that to:
“The family is cooperating.” And that they wouldn’t “rule out” a criminal investigation.
But the horse is out of the barn.