I figured it out. Well, actually, a helpful soul on irc.freenode.net #sme-en showed me how.
Anyways, for anyone that needs to do this, here is how:
db accounts setprop %USERNAME SortSpam disabled
signal-event user-modify %USERNAME
After that, that account should no longer have a spamfilter (ie. SpamAssassin). You can verify this in the following file:
/home/e-smith/files/users/%USERNAME/.qmail
It should read "# sortspam disabled " near the bottom.
-ltwally