To decide if an apology is needed, determine if the issue is one of competence or integrity. Competence problems involve a failure of reliability, while integrity problems involve a failure of responsibility. Apologies are effective for competence problems, but denial is better for integrity problems, assuming the company acted with integrity.
Competence problems are easier to forgive, while integrity problems are harder to overcome. Diagnosing the type of trust problem is the first step to an effective response: apologize for competence problems and deny integrity problems if wrongly accused.