We always recommend to clients to admit to errors and mistakes immediately. That way, you can spend valuable time working on rectifying the situation and rebuilding trust with your stakeholders, which is important in reputation management.
Yet, it’s still a common tactic for people to not only deny fault or avoid acknowledging the situation but also double down on claiming that they had made no errors or mistakes. The result is that they’ve made the situation worse and last longer than it should.
Recently, McDonald’s had an E. coli outbreak linked to contaminated ingredients–likely its slivered onions–resulting in several cases of illness among customers. 
INTRODUCTION