Really? Huh. Must be my inability to read, but I thought for sure that I saw the following quote in Breyer's dissent:
"[W]e held that the “common-law ‘knock and announce’ principle forms a part of the reasonableness inquiry under the Fourth Amendment.” (BREYER, J., dissenting op. at 2).
In reference and in context to the quote in the original post. Don't play these semantical games with me - I'm way ahead of you.