I agree the business (not just the boss) has to know.

I proved this once when I accidentally screwed something up on a production server. I fixed it almost within minutes, but I still told the boss (who is non-technical) what I did. As I'm the only technical resource at the time and no one can double check my own work but myself, I took it upon myself to let the business know.

My boss was kind of puzzled and asked me why I told him if I just fixed it anyways? I told him because even though I still fixed the problem, I still made the mistake. If I don't tell you, then no one will.

Through practices like that, I built a strong trust with my boss. That's the return on investment with transparency.