Hmm... I guess I'll have to go watch it that episode again, because it sure sounded like a blooper to me. Probably because it was Jonathan Frid, and the strangeness of the line combined with the fact that Frid was known to occasionally mangle lines just said to me "blooper". And yes, MB, only DS could make such a line make sense!
For a real Frid blooper, my favorite is his Yoda-esque "This night must go nothing wrong." (But I'm fully prepared to be told I've misquoted him...)