Yep, you are correct. Here's what I did to verify this: My 'box is set to widescreen, so I loaded up the first level with Kelly as a reference shot. From her starting position, I measured the distance between the two angular points on her back. With the tv in 16:9 mode, the distance was 5.5 inches. In 4:3 mode, the distance was 4.25 inches. I then switched the 'box to "Normal" (boo MS!

) and reloaded the same level & measured the same distances. Widescreen: 5.5 inches. 4:3 mode: 4.25 inches.
If the game was widescreen, the proportions would've been different between the two Xbox settings.
I should've caught this a while ago - I even posted a rant about how Sega has a tendency to make their game characters overly tall and skinny (re: Beach Spikers, NFL 2k3), but still didn't make the connection. Oh well...
-Dave