Don't assume a deal is done until the deal is finalized both verbally and on paper; otherwise, there are a myriad of reasons why one side or the other can back out at the last minute -- most notably perhaps, someone says the wrong thing at the wrong or the last moment, and capufff...the deal is gone...
Don't be presumptive and don't say something stupid in the heat of the negotiation, especially when it's coming down to the final lap. Otherwise, you'll be swinging at air, and going home with no signed cheque, nothing to celebrate, and the deal that got away...
-- dgb, April 19th, 2011,
-- David Gordon Bain,
-- Dialectic Gap Bridging Negotiations...
-- Are Still in Process...