As others have noted, my understanding is this is pretty standard procedure unless they really think they've caught everything very early....docs and opinions differ on what to do if they find cancer in the lympth nodes. I was told that if they find cancer in the nodes, they'd sew me back up and spare me the morbidity of the operation--- however, as Swim noted, there are differing opinions on this....
I have a little story on this to share....prior to my surgery, I explained to my wife that the procedure ought to be 3-4 hours. If they come to get her really early, brace herself because it would mean they found enough cancer in the nodes to scrap the full RP--- and that would be a bad thing.
about 20 minutes after they took me in, my wife, who was in the waiting area with her sister and my sister, gets called up to the desk, where the nurse cheerfully chirped that I was all done, and the doctor would be in to see her shortly. She starts freaking out, as does my sister.... the nurse can't figure out why everyone's upset. My wife's sister is the one that smells a rat, and they tell the nurse to double check -- that I shouldn't be done just yet. Sure enough, it was some glitch on the notification system.
My uro, who's a bit of a bad-ass, was not pleased when he heard this story later --- I'm sure some poor nurse got chewed up on that..... my nodes were clear and we proceded as planned....weird stuff!