If you look in any medical chart, you'll see signatures and initials everywhere. Every test is initialed. Every study checked off. Every call to the doctor noted. This is all done for one reason: liability.
Somewhere along the line, we decided as a society that the buck would stop at MD, and so it is the doctor's responsibility to ensure that care is appropriate, and if malpractice does occur, the doctor is the one who is responsible.
This all sounds very reasonable until you consider a few circumstances. The doc is liable if a test is done and the report not sent, but the test is markedly abnormal. The doctor ordered the test, and should have followed up on the result.
The doc is liable if he orders a medication that is not administered over the course of a hospitalization. He ordered it, and should have ensured that it was given.
My point here is that there is only one person to blame for all these mistakes that happen, and that person, if you have MD after your name, is you.