This combo in the video IS an infinite until the AP thing sends them flying it's not like there would ever be a point where Nathan can't hit the opponent cause they're out of reach so if that mechanic wasn't there it would go on forever. The ones I noticed with crumple and stuns in rekka's turned out to be random so while they're potentially infinites too you can't control the outcome of the last attack but if you could then you would indeeed get infinite combos that go on until the AP burst.
It's still an insanely easy way to build meter unlike other characters who need to constantly chase down the opponent or find ways to keep them juggled.
Come check out my Twitch TV channel, will be streaming various PS4 games from time to time http://www.twitch.tv/reddaxel
Hey guys, creator of the video here. I was thinking this may have been a legitimate infinite considering the infinite prevention system hadn't triggered despite the AP bar continously accumulating meter at the bottom, but Maj of Superbot had confirmed that it wasn't a bug with the infinite prevention system, but a minor bug with the AP meter at the bottom, which misled me. It IS an infinite in the fact that, you can keep them in hitstun until the prevention system kicks in, but nothing more than that.
I have a much better, updated video showing an example of a full long-range hitconfirm with the opponent airborne here: