Not sure it was a technology problem or a process problem. The mud loggers (engineers) on site noted a serious pressure problem while the well was being flooded with seawater to ready for a cement cap.
The pressure was 1400 psi, way too high for the manover they were trying. The rig people wanted to refill with drilling mud until the pressure could be explained or mitigated. The BP manager on site said no. Continue with the sea water. The rest is history.
Technology is only as good as the people who use it. And in this case, mis-use it.