Honestly, though 31 hours seems a bit excessive, I don't blame them for being cautious. If it was a body, they'd be smart to document everything in the area and carefully navigate so as not to contaminate the crime scene. Lots of important evidence could be destroyed by someone just walking up and moving the body.
I'd rather them be careful and thorough with what turns out to be a sex doll than be callous and clumsy with an actual body.