The "uppercut" is the correct animation for Guard Breaker. However, I've noticed that it's sometimes replaced by other animations (like Maki-Otoshi), which is a bug. The animation you're describing would apply to Ki Burst from Aikido Grandmaster (which is, though, combined with quite an intrusive effect) and one variant of the Lupine attack.
guard breaker
5 posts · 2006-05-16 03:25:00 to 2006-05-18 03:49:00
In tracking down this kind of issue its good if you report what style and tactic your opponent appeared to be using when the animation played.

I'm all ignored: 
http://mxoboards.station.sony.com/matrix/board/message?board.id=cr20anim&message.id=629
From what others say, I think it's pretty much any style and tactic. However, I only saw that when I was using Aikido, where it was often replaced by the Maki-Otoshi animation. As far as I recall, the tactic was irrelevant.
Hmm, I've seen Guard Breaker playing a wrong animation in the center of a standard mission room. Also, I've never seen any animations not playing or playing wrong because of lack of space. You still can perform the Machinegun Fist Combo right in front of a wall, and you actually kick your enemy away. It just won't look that good

Message Edited by zeroone5069 on 05-18-2006 04:33 AM
Machine-Gun Kick, sorry