some DVC members set up a conference call with the renter, but that can be complicated.
a few days before travel, the renter can call the resort directly and they should have the information in the system.
you can get a copy of the confirmation mailed to you shortly afterwards, but as you seem to understand, the reservation is still in the control of the DVC member (i.e. while it's unlikely that they would cancel out of spite, they still have the power to do so.)
if you want to save money by renting, trust (i.e. worry) is just the price you pay (along with limiting your options for cancelling the reservation.) i decided it was easier to buy a small contract myself...