The facts as such are that the Singapore maintenance facility used staples in a procedure that QF admitted was incorrect.
This leads to 2 questions.
1...Did the facility know that they were not supposed to use this technique?
or
2...Did the facility know that this method was incorrect but used it anyway?
Either way would anyone after seeing this have them service your car let alone a commercial aircraft.
You would have to assume that if there was one instance then there will be others.
If you found a car dealership had used a dodgy repair method would you go back to them?