Recently there have been several runaway dollies and plane strikes. In many of these accidents UPS management has been able to prove that methods and procedures were not followed, which can lead to discipline.
In order to safeguard your job, please follow all of your training and methods. It is your responsibility to walk off the pins and couplers each and every time you hook up to a train of dollies.
Following your training and procedures are part of your job, but doing so also protects you from having runaways, which can be a terminable offense.
Always remember to protect yourself and your livelihood by following the procedures the company has trained you to do.