This tip will basically work if you have a cell phone. When entering the office to speak with the principal/vice principal/teacher/etc. Have someone call you on your cell pohne and hang up when you pick up.
For parents ONLY, Say something similar to the following:
Hello? (your friend should be hanging up about now)...Oh hi mom!!hows dad doing...what....when?....on the parkway or in town?...........oh my god dont worry ill be right over.....(hang up)
Say this to the teacher, etc.
mr./mrs. whatever, my father was in a car accident about 10 minutes ago. Im so sorry. I'll call when this all gets straightened out....when did you say his detention was?
The authority figure will feel bad and call it off. If not...he/she can sense tricks as well as my wife...which means they're pretty damn good.