I agree with many others....we should reserve "Pilot Error" for those situations where the Pilot(s) intentional violate SOP's, Procedures, Regulations and use the Term "Human Factors" to describe these kinds of tragedies where good Men make mistakes that are the result of many factors largely outside their control and doing.
And I have to disagree. "Error" implies a mistake, an unintended occurrence, or perhaps something you did mean to do, but the decision making leading up to the occurrence was well-intentioned but erroneous, however it is caused.
Intentionally violating SOPs, procedures and/or regulations is not an "error", as the course of action followed was not unintended. That is where the word "negligent" starts to rear its ugly head.
"Human Factors" is very probably part of the chain that led to the Error being made, but to describe every mistake as simply Human Factors is, to me, too simplistic.