One of the points of the author was that if engaging in that behavior does not put anyone in danger it is acceptable; however, it can be argued on the morals of the individual. For example – cheating, just because 99% of the class is cheating in an exam does that mean its ok for you to cheat as well? that is something morally questionable in that case.
In Kant's categorical imperative- Kant is worried about what is morally right. One example is being stuck in a line with an indecisive individual at the head of the line. To speed up the process one could consider hurting that individual to get them out of