I also learnt that when a tester complains about a problem you were already aware of the list of
acceptable responses does not include "I didn't think you'd find it"
Many years later, after I'd avoided the customer care course, the following events took place
1. I found a bug in some code, only a couple of days before we released it
2. Discussed it with development manager
3. We agreed that it was a very unlikely situation
4. So we released the code unchanged... our testing was 95% complete
5. System test found it on day one of testing
6. They reported the problem
7. I looked at their error log
8. It was exactly the same as mine
9. So I said "Yes, we know about the problem"
10. I explained the situation under which it occurred
11. Tester asked "So you released code with a known problem?"
12. And I replied "Well, I didn't think you'd find it"