First I am a fan of these shows even though as toi read this toi will question that.
They spend a great deal of money and are called par some experts but they use highly questionable methods in almost every case.
First they tell the investigators what to expect. toi never do that if toi want to verify something, toi allow everyone to find what they do then compare to see if they match. This way toi get accurate information and i would guess a lot less of the: "Did toi see that?" When there is no way for us to see because the camera is always in the wrong place. There are cameras like those used...