I mean it's very very believable...The cats react to every word he says like it's real...He stops talking once the cat has jumped...He kisses for the cat to look up when it's looking away and he says "look at me"...You can hear the echo of things moving while he's yelling..Any proof that it's dubbed over? It must have taken some amazing editing if it was..Especially weird considering the video quality is crap
It takes nothing to dub an audio track over a video, here is one example with a low level video editing tool
You would record your remarks then move the track over a bit to the left and it will give the illusion you are talking before the cat did the action
Even something like this showing a chicken at the Olympia conference on stage takes 5 seconds to do today, experts with this stuff can do things that use to take weeks in a matter of minutes
check the video of the chicken that escaped from one of the bodybuilders bags and made it on to the stage
https://vid.me/2sDH