What is potentially unethical about the situation described in the Daryl scenario is the choice of not informing my superior of the shenanigans my peer, Daryl, is committing. That, basically, is the theft of company time, company equipment and company staff for his own personal benefit. The very fact that I would be fully aware of his deliberate underhanded actions, and that I would continue to be silent about it, I think, would make me almost as culpable as him. Close to a co-conspirator, but not quite. Although, I would not be actually participating in this disreputable manner, I would by virtue of not saying anything would make me, at the very least, tacitly giving approval. And, if my boss were to find out in the future for some reason or other that I was fully aware and said nothing, it would not be unfair to say an outright dismissal might be appropriate in the eyes of my employer. At the very least, I would appear to be a not too trustworthy or dependable employee.
To know something and not say something because perhaps one did not wish to, but into anyone else’s business is one thing. But to not say something for self serving reasons is another. If I were to keep my mouth shut so that I may do the same thing as Daryl i.e. use company property, use company time and use company personnel for reasons that have nothing to do with the company, is to use an unprofessional word: scandalous. This kind of behavior is outright theft.
True, one may feel a bit like a tattletale if one were to choose to inform their higher-uppers. But so what? Better to be that than to be the kind of employee no employer desires to have. And besides that, it would all be Daryl’s fault if he did get busted. After all, he would be the one committing this devious behavior. That does not seem like the kind of person that has any company loyalty.