But what I'm asking about is if you have the Bitcoin-Qt client and it is not currently sync'd, but then create a new spend transaction. Are you claiming that the transaction is then broadcast to the network immediately ... before sync is attained?
Yes - I do this *all* the time (as I don't normally run bitcoin so my client is *never* in sync when I start it). You have to wait until the GUI *appears* (so you can't do a tx *instantly*) but you certainly *do not* need to wait to be in sync.