Depends if you are looking from outside of the company or within. If outside, then the Boss, if within, then the worker; unless the Boss had agreed to take on the responsibility.
If I am mainly responsible for a project and I fail to bring to the boss’ attention something that could have important implications, and I do nothing about it myself, then I am clearly in the wrong. However, from outside of the company, the Boss will always be in the wrong e.g. bosses can get prosecuted for manslaughter if someone is killed on a property they are in charge of, even if they are not directly involved in the incident.