Again, from the perspective of a police officer and police diver, things that are apparent clues at the beginning of an investigation do not always lead to the solving of a case. Many times things are, found to be, not what they are made to appear. This may or may no be the case. Every search I have done, in the water (diving), or say with a police K-9 and his handler on land, has not always found what we wanted to find. Sometimes we just ruled out where something wasn't. That is all part of an investigation.
A bank robbery, for example: The dog pulsl really hard to the next parking lot and behind a dumpster. Then he shows no interest at all. You cast him a round some more in other area's and he shows no interest. Put him back on the initial search area, he shows interest again, pulling hard to the same dumpster. That tells me a car, or means of conveyance was parked there and bad guy ain't there no more.
The initial evidence, and the vehicle and log books, and interviewing family, co-workers in PCB, dive shops, etc are all part of trying to rule out where he isn't. You can bet his finances, tax records, phone calls, everything is being looked at right now. The sheriff has a case that he can not afford to go unsolved. I said, somewhere before, this is a homicide investigation until proved otherwise. A homicide is any death that is caused from un-natural causes. If there is ever a question in a death, or what appears to be a death the investigation has to be done this way. You can never go back and get evidence once you leave it.
There is also a huge sign of a submerged body after say 3 or 4 days under water that is not cold, though 68 is cool, it is not cold. Search divers should have thrown a clue, that would have been overheard, that would be pretty much proof positive. Maybe they did. I wasn't there. That sign takes the glamour out of being a recovery diver real fast.
As for dogs on the scene, dogs (like us) have bad days too. Also many dogs are said to have a certain type of training, and may not. Don't know about this issue, wasn't there. A certified cadaver dog will eliminate anything but human decomposition. In most searches, a minimum of 3 dogs will be used and they will enter the area from different locations. There is a lot that we may never know.
The discussion here has certainly brought up a lot of good stuff, not so good stuff, perspectives, things we never knew before and what can happen. Let's just say this turns out to be a big hoax..... does it change the stuff we have talked about, or make the things about diving in enviroments we are not ready for any less right? If this ends up "didn't happen" remember, it sure could have and the things that were discussed have made everyone a little more in the know about the sport we love and do for fun.