• But how do we spot errors in report itself?
  
  
  

1. We know that an accident happended.

2. Investigators have a theory that an 
accident will happen IF some conditions
hold.

3. THEN we must show that those conditions
did hold if 2 is to explain the accident

4. If we cannot achieve 3 THEN we need
to find another explanation of the failure. 

• Mathematics prove reports are incorrect.