I was a prosecutor, and I am now a civil litigator.
Further, an alert to the presence of drugs is totally different than commanding a dog to speak.
An alert is when you tell the dog to find the drugs, and then the animal unilaterally gives the signal that drugs have been found. There can be a multitude of different "alerts" such as sitting, scratching at the location of the drugs, or barking in conjunction with the others. It is not barking alone. The alert is performed unilaterally, after the command is given to search for drugs.
If the police officer commands the dog to speak, then any such command will be on the dash cam (which also records the police officer's voice), and the search can easily be deemed unconstitutional, and any evidence which resulted from this search excluded. Where I live the dash cam automatically begins to record when the emergency flashers are activated, and this is how the vehicle is directed to stop. They (and the dash cam) and are not turned off until after the stop is completed. It is kind of hard for the cop to command the dog to issue a false alert under this scenario.
Additionally, watch this video.
http://www.youtube.com/watch?v=mmJ2kXVcHYE
no barking.
next is added after the post was submitted:
you also refer us to the Supreme Court deicision of Illinois v. Caballes and state to pay attention to pages 8 & 9. Are you talking about the dissenting opinion? The opinion that is not law?
also, in response to your www.wfsu ... link. Did i not mention that the dog has to be reliable.