Jack,
I understand that there can be 22" splash cymbals, but I really don't think Stewart had any--especially in this video-- when he did add splashes to his kit he only used small ones.
Not sure where you're thinking he is using a crash as a splash in this video. Sounds like a crash to me, no matter where he's placing the hits.
Also, drummer friends of mine would argue that a 22" splash is really more of a medium thin crash cymbal.
To me, a splash (and Stewart's use of it) is more applicable here:
http://www.youtube.com/watch?v=JwnMG5yG ... re=relatedespecially at 2:47
by this time he had added splashes to hit kit, along with the octobans.
Just my views, not trying to start a major debate here...peace.