Hi, I heard about this being discussed today at skydive San Diego so I'm joining the discussion. Yes, it was me who had the pleasure to experience the two out.
I'm replying to BigSky because that's exactly what I did. Unstowed the front (main) canopy's brakes, and didn't touch the rear at all. Or I should say, I immediately unstowed the main brakes and I realized that I had two out.
I only had 33 jumps, and being unexperienced, it took me a while (5sec or so) to figure out what happened....It got to me when I saw the reserve bag escaping from me.
So, I kept my cool and decided not to touch the reserve brakes because two canopies opened very nicely and I figured I shouldn't do anything stupid. For a half of a second, I thought about cutting away the main, but then I didn't (because I didn't want to do anything stupid). I'm glad I didn't.
As you can see from the pictures, the main was in front. So I decided to use the main toggles (which had already been unstowed) to stir. I figured that front canopy will catch wind faster, so I can stir better. And it allowed me to keep good control.
As BigSky suggested, I made sure that I only make a very slow turns, and I changed my position 90 degrees to head towards the drop zone.
After that, I didn't do anything but let the two canopies glide me down. That's all I did.
I really don't know why the reserve deployed. All I did was deployed the main at 4000, and two just deployed simultaneously. Only speculation I have is that I was scrunching on the back of the small plane, and I changed my position with someone and my back was rubbing against the person.....but I don't think that will really pull the reserve pin out....so I don't know.
Anyway, after that experience, it really made me want to study more about the sport. It also made me want to buy my own rig (oh, I didn't mention yet that I was using the rental).
Today, I went to the same DZ again, and had a couple of nice fun jumps. I guess people into this sport are all crazy.