I think we are getting a little hysterical about this. It was a nudge to the shoulder. It may have slipped upwards a little bit but I can't see in the video how it actually got him high or above the shoulders. Smith instantaneously grabbed his ear to try and milk a free, he didn't seem to actually connect with his ear.
About whether it was a dog act, I don't think so, Smith whacked him and ran away, turning around doesn't mean you aren't going to get one back.
Where Conca got it wrong was the timing, he needs to learn to take his whack and wait, it's funny how quickly the chance to get them back can present itself, even better if you can make it look legal like crunching your knee into their ribs in a marking contest.