Also to be clear, reasonable suspicion and probable cause are not the same thing.
In this case, reasonable suspicion would be whatever the justifiable reason to detain the man while the other officer arrived was. This is what the court said was missing from this case.
Probable cause is what happened when the dog alerted to the scent of drugs. The dog's alert was the probable cause needed to justify the search of the vehicle.
Probable cause is a harder thing to justify than reasonable suspicion.