The issue is too complicated to cover adequately here.
Most accidents involve multiple failures of different components of the system.
It is rarely possible to pinpoint one particular failure as the sole cause. There are often powerful and compelling reasons for wanting the blame placed on the human. The human is often called in to save the day after chaos has already begun and then expected to come up with a miracle. Most accidents result from unanticipated events and conditions. Thus it is doubtful that computers will be able to cope with emergencies as well as humans do.