The dead give away was from the start. The speaker on the plane is in the nose cone, in-cowl muffler and for that matter no muffler would have enough room and you can see there is no pits muffler. And nitro doesnt just start ya gotta have a starter, you dont just put the throttle forward and it starts.
i believe they make remote starters. one of our local pilots had em on his pattern ships.
i've also seen a couple companies that offer scale exhaust. they actually build exhaust stacks to come out in the proper place, and if that was a gas engine we wouldn't see exhaust. if it were nitro, we would've.
i did notice the restart though after he nosed it over. that would lead towards electric, but i've still not seen an electric that could fly on a 4 blade prop before.........
i still like mine with the ys 4 stroke in it. she flys beautifully. fast, short or scale takeoffs, and nice gentle landings.