JKR really missed out on the sheer fun to be had in writing that scene. How could she not realize what a great dramatic opportunity she had there, and what a fabulous coup a final Snape/Harry confrontation would be? That's half the joy of writing! She spent seven books working up to a delicious moment - the kind of moment most writers slave to create - and then she just blows it off! *shakes head* Gah, I'll never understand.
i'm stalling a bit and trying so hard to get back on track
I think you're in good company in that respect. *glances around* There's quite a crowd over here in the stalling corner.