We got into a discussion about why. One of the techs said that he sees people waiting to do things rather than going ahead and getting everything done. The owner of the company, who was sitting in the meeting with us, asked how many times that happened. As it turned out, only twice. One of the times, the daughter had to get permission from a parent. The other time, someone directly said that they would wait and see what happens. In more than 150 service tickets, only one time was the work refused until later.
This proved my point. Most of the time when the technicians recommend additional work, it gets done - as long as the customer trusts the technician. So, I reminded the techs that it is important to write everything down and review their recommendations and observations with customers.
I started thinking about why this might be happening. From what I've observed, technicians have a tendency to remember the no's and forget about the yeses.