(urth) Wolfe's brilliance or my denseness?

[Lee Berman]

>Jerry Friedman: I'll bet you have no trouble saying "smoke" or "Cass does" with an /s/.
>My intuition for "Casdoe" is a /z/, though, like yours.  I doubt it matters.

I have no trouble saying "smoke" because the "s" is not in the middle of the word. I can
say "Cass does" easily IF I say it as two separate words. If I say it quickly, as one
word, the difficulty returns.
 
I'm not saying the difficulty is inherent in human tongue function but rather a function of
my AmE trained tongue and the linguistic rules it has learned over a lifetime. It only matters 
as the point of a hypothesis for why non-native speakers of English are more likely to have caught
that Cas was Dorcas.