A decision

Today I saboed my classmates : in the morning they were late but did not get a late slip when i asked for it they shouted at me saying they had stomachache!!! How rude, the angry me decided to tolerate, then they threw me a unsigned late slip, i didnt accept it! then they asked my class prefect to sign it, so this late slip is a fake so i told my teacher.... they got their serious punishment  >>>>> did i make the right decision, i was just doing my job, but they disappointed me being my friends i wanted to help them!!!!