Once I realized what he was doing, I realized that the Strategy pattern was applicable in this case…but his chosen example was dumb and one that I wouldn't have used to demonstrate things. As expected, he told me to supply a sample of a better way. I did, telling him that the sample would be better if he didn't mash the logging level together with the message.
Included in the post is sample code, first showing the initial version of the logging class, complete with accompanying tests. Following that, he shows how to refactor it into something using the Strategy pattern, replacing the logging type switch statement with protected methods for each logging message type (critical, notice, etc).