After Helen Cho regained her self-control, why did she insist that the Regeneration Cradle should be delivered to Stark? Why not just destroy it? Did she know Stark would use the synthetic being for the birth of the Vision?
Remember that Ultron is one of Stark's creations and the cradle contains a physical body for Ultron. The problem is that they can't just destroy the cradle because the Mind Stone is in there. From the transcript
Dr. Helen Cho: He's uploading himself into the body.
Steve Rogers: Where?
Dr. Helen Cho: The real power is inside the Cradle. The gem, its power is uncontainable. You can't just blow it up. You have to get the Cradle to Stark.
Tony has made this mess and it falls to him to fix it. Blowing it up (the easy path) is off the table and (as the subsequent scenes show) the other Avengers want to know how he's going to fix it as well. Nobody foresaw him making Vision before Bruce sees where Tony's train of thought is headed.