I know of four instances where checklists (proceedures) have been changed.
The first resulted in Britain's worst avaition disaster.
The second resulted in our N reg 747s being banned from US airspace.
The third you can read about in a CAA incident report where the crew put out a Mayday.
The forth you can read about in a CAA accident report.
A no brainer IMHO.
Generally those that build the aircraft know more about it than those that fly it.