Joe does taxes for his clients and brags about how he always makes his clients happy by under promising and over delivering.

Joe does taxes for his clients and brags about how he always makes his clients happy by under promising and over delivering. When asked what he means by this he tells us that he estimates what a client will have to pay or get back and then gives them a much worse number as his estimate. When the taxes come in at the better number (the one he estimated originally), it looks like he was able to work magic and is a hero. Discuss the ethics of this scenario.