A. Acknowledge that there have been no failures of this complicated technology and, therefore, it must be totally proven. Really large and successful companies are your subcontractors and have done this dozens of times. So this first choice is to improve the project economics and lobby the government's witless regulators to allow some shortcuts in procedures--surely okay as there have been no failures.
B. Don't look for shortcuts and follow proven tests and procedures. At least all proven safeguards will be utilized.
C. Do the calculus. Presume a failure even if it is of low probability--presume it because of the immense impact. Determine a course of action upon such a failure--ahead of time. Test it--in the labs and in the field. I know it's difficult and costly but better be prepared.
Of course the only rational answer is C. This isn't an oil question, it's a question and decision concerning any business condition with the stated parameters. BP and all other drillers dealing with unbelievably difficult circumstances (simply stated--depths, temperatures, pressures and unforetold circumstances) that are amazingly extreme. You don't need hindsight to understand the extreme circumstances, the stresses impacting technology, and the incredibly large and uncontrollable results of a failure to know that C is the only choice. BP and all other deep drilling oil companies chose A. They chose to assume there would be no failure instead of investing, say 2 or 4% of their potential profits into a backup plan.
Build a cap (the structure currently being utilized), test it (not easy but figure out how to do it), test oil and water mixture under the observable environmental conditions (whoa, it crystallizes), figure out how to deal with that (install mixers?), test it again, and when a solution is viable, get the equipment located in the Gulf on standby. If that doesn't work, always have two parallel drills. If that is completely cost prohibitive, figure something out. With enough forethought, having a proven backup plan is just common sense.
These companies are amazingly greedy and stupid!