Time to eat my words, folks; Danielle used the Veto.
The scrambling and deal making between the Veto win and the Ceremony was Big Brother at its best. Multiple alliances were formed and revealed, and the most relevant to this situation is now called the Silent Six.
After Dani won the Veto, Boogie turned his game on full blast. With Frank in peril, he knew that now was the time to form a majority alliance with the people who have been dominating competitions since day one. As Shane and Danielle are the only Veto and HOH winners to date, besides Frank himself, he set up shop in the HOH and proposed the following; a final six deal with Dan, Danielle, Britney and Shane. Thus, the Silent Six was born. They whisper huddled and everything.