Is there variability in how toxic acetaminophen is to the liver depending on the person?

I was thinking about how athletes with injuries sometimes get hooked on opiates, and one was taking the yellow Norco 10/325s double digit at a time, which means that he was consuming 3 grams all at once. Yet, I have read many reports online of people going to the ER with acute liver failure after "misreading" the tylenol dosage info. How can one person take so much APAP and NOT get liver damage, while another seemingly takes a bit over the 1 gram max. at a time and gets liver failure?