It's pretty believable.
Just since I'm a heavy player of that game, First you attack he blocks using focus, hits with focus, dashes into a solar plexus strike, into a crouch low punch, into a heavy punch, into a EX Tastumaki. So that should be about a halfway (but still useable Ultra bar) Although, I'd figure that he'd stun you around the 4th kick on the EX. Which would give him a massive combo, you must have been lucky that you didn't. O.o Then you go in with a jump heavy kick, into a heavy punch, with a heavy gadouken and heavy dankyaku I presume (For the stun effect). Stupid of him to just pull off his Metsu like that without a combo. It enabled you to use yours and get your invincibility frames first. Although I DOUBT that your ultra would kill him at half power. Unless you both had handicap on or something. Going as an NGer though, I'd have to agree with Ace. It's nice but not front page material. Sorry.