If you arrive after the start of class, you are responsible for informing the instructor. Remember that the mental discipline of kendo will help you in other endeavors. It must be exercised to be strengthened. It only takes a split second for an accident to seriously and perhaps permanently injure someone. You should carefully inspect and maintain your shinai.
Splinters can be much more than an annoyance.
A shattered bamboo slat can be tragic. With care this equipment will last many years. After the class ends return your bogu properly to the storage area. If there is a problem with your bogu report it to the instructor immediately. The shinai are available in the Cadet Store.