I’ve only seen one or two episodes of the show (not my cup of tea), but in each they sent some intrepid young staff to break into someone’s house searching for clues. Not, “go knock on the door and ask for permission to enter” but actual breaking and entering. And in both of the shows they didn’t just go to the medicine cabinet and look around, they went room to room searching, swabbing, collecting, and Scooby-Dooing. I don’t remember what episodes they were, but I think in one the power was out (or was that for mood-effect, like on CSI?) and there were rats or birds or something dropping red herrings on main characters).
I’m sorry, but I’m having a hard time finding this legal. There is a doctrine of necessity as a defense against trespassing (if I remember my terms correctly), such that if, say, your boat is in danger of sinking in a storm you can use a stranger’s dock. However, this suggests that it functions as some sort of Good Samaritan law to protect anyone acting in the interest of a property owner — it implies that if I find you out cold in the street I can go to your house and rummage about in search of a “clue”.
I also have a hard time buying the “not a state actor” bit, seeing as how the setup in the show kept implying Ultimate Peril and that there was an unconscious patient with no person to give permission to enter the property (else the whole thread would be moot).
Of course, whether it gets done or not and whether or not people are lucky enough to get away with it on a regular basis is outside the scope of the OP. And any jurisdiction is free to carve out safe harbors where they will, so there will be some variation. But it strikes me as opening the door to a lawsuit, licensing problems, and possible criminal complaint.