When asked to give examples on the weaknesses, you need to think very carefully, and plan in advance what your response will be, as many people dig a very deep hole here. A good response to the weakness quoted would be:

I had a situation once where I knew that a more experienced colleague was regularly absent from work following nights out drinking, but she would say that she had a migraine. When this happened my workload increased significantly. I undertook this willingly but I must admit I was annoyed that this person was taking advantage of me and the company. However, I decided to let the supervisor do their job and just get on with mine. In quite a short space of time, the issue was addressed and the problem was resolved.