Generally, there are images captured that will not represent your best "professional" work. I tend to edit these parts out and leave them on the cutting room floor. Only on an event coverage job will I find it acceptable to give a client all of the footage.
There used to be a business part of DVXuser. For the life of me I can't find it. I'll leave it here for now. Good info.
I am not a lawyer... thus, nothing I say should be taken as any sort of legal advice, but if you consult a lawyer, I am pretty sure that if there has not been a contract signed that says otherwise, the person who shoots it, owns it. This will certainly piss off the client, so be prepared to pull this card once and pull it hard. They will likely not come back next time, even if you are willing to sign away rights in the future.