We know from Clint's account that the dog (which dog--the inside or outside or both, we do not know) woke him barking. I may be reading too much into it, but I think the dog probably would have had to be barking in a continuous or frantic way to wake Clint, since his door was shut. Still, if the perp was not expecting anyone else to be there, the dog would have been of no consequence. A yappy house dog, sealed in the house, is no threat--just a nuisance. The house is so isolated that I also doubt the kidnapper would worry about a barking outside dog attracting any attention.
No one has answered my question on this, but I am betting from seeing the picture of the attached garage, that there was no door going directly from the house into it. I know that will be a controversial statement, but i cannot figure out where a door would be. The door in the kitchen that used to go to the other garage was on the opposite side of the room from this add-on garage. The best I can figure, you had to go out the kitchen door that went to the deck, and then turn left into the little breezeway to enter the garage. From the interior interviews posted in the media, you can see one door exiting out near where the pool sits, and then there is a small kitchen window to the left of the paned kitchen door. My bet is that you might be able to look out the kitchen window and see part of the garage-- the part where Holly and the camo man were seen crouching or sitting on the floor when Clint looked out. I doubt the perp heard Clint in the house, since the garage has its own walls of steel, and then there are the outer walls of the house. Unless Clint called out to Holly, which is not recorded as having happened, I really doubt the abductor ever knew he was there.
Clint could have even unknowingly been in danger had he revealed himself. It is likely the abductor had a weapon, and he might have used it on Clint to be able to take Holly without leaving a witness. It would seem that fate kept the Bobo's from losing both children that day, possibly! Based on the information we have, I don't think that Clint perceived any danger, and hence, there was no reason to interject himself into what he thought was a normal conversation between boyfriend and girlfriend.
Of course, this is all conjecture, and JMHO.