I dunno. I've seen that same patient, nonplussed look on other dogs, when dealing with immature...puppies, kittens, humans. If you jerk your dog's tail, he's gonna show teeth; but I've seen a big, smart dog like a Lab or a Shepherd let a baby pound its head or body, and just look with a "Why me?" expression.
I'm convinced they can smell immaturity. A Shepherd is genetically programmed to manage dumber animals like sheep, so, if it's fed, it's not gonna eat a kitten. Actually, in years of watching dogs, I haven't seen too many that are eager to go after cats - Huskies being an exception. My mother's greyhounds were eager to make friends with the cats she had, before she got the dogs...it was the cats that weren't having it.
This kitten is going to not have a canine-phobia, seems.