OK, we can all quote statistics, bend the argument any way we choose and frankly, I am not going to engage in an argument with Bob or AnFI about singles versus twins. Even if I was convinced, my workforce would not be.
A "successful" ditching is considered a risk that requires mitigation in my world as we would have people in a life raft (or not) bobbing around in the water 200nm from the nearest facility or rescue and who have to be recovered. Perhaps we should tell them to treat it as an unexpected "cruise"?
Of course, there are other things that can cause a ditching but wherever we can reduce the risk, we will do so and flying a single when a twin is available isn't even worth discussing.
How about one-way fuel, if we miss the rig, we will just carry out a controlled ditching, hmm, I must rush upstairs and tell my bosses I have found them a way to save lots of $, I will have my desk packed so that I can leave straight away!
Under your logic, a single engine A380 with a big parachute a la Cirrus would also be acceptable for trans pacific flights?
Have fun debating it, I am not going to argue or offer my point of view anymore. I will stick with my heavy twin fleet thanks.