Dave Plummer, the creator of the original Task Manager at Microsoft in the 1990s, encountered an issue where CPU utilization readings occasionally exceeded 100%, which he suspected was a bug in the kernel. Despite being a user interface designer and facing skepticism from the kernel team, he implemented 'asserts' in the code to diagnose the problem. One assertion specified that CPU usage should not exceed 100%, and he embedded his name and home phone number in the code for anyone who might encounter the issue. No one ever contacted him about the bug, and it remained unresolved until the kernel developers identified and fixed it later.