Having worked for both European owned and US owned oil field companies, I found that safety and engineering procedures were dictated by the head offices. Cowboys, at a local level who flaunted or ignored either, were relieved quite quickly. In fact, the review of accidents, contributing factor, prevention, recommendations for future prevention, etc, were readily available to the rest of the oil sector, with change quite readily adopted. Granted some of the safety features of North Sea rigs are not adopted in other parts of the world for obvious reasons, this also applies in the reverse.
Engineering procedures are vastly different from field to field and even vary well to well in the same field. New technology, equipment, support material, etc, seem to change/improve after they have been found to function as required. Many times this comes about as more hostile conditions are encountered. If Engineers could foresee the unknown and plan for it prior to it rearing its ugly head, The industrialized world would be hard pressed to accept, what could be called future tellers.
In my opinion the BP blowout was not caused by ignoring safety regs in place or the need to add more. The info would indicate that Engineering procedures set out prior to drilling the well, standard oil field practice, and procedures were ignored, even when pointed out to the BP personnel, by third party people. If this was due to pressure in regard to 'bottom line' or perceived time schedule deadline , will probably never be known, other than by those directly involved.