I believe IMHO some people have organs that are more resilient. Just for giggles look at Kieth Richards, Ozzy Osborne, Willie Nelson and many of the old time drug and alcohol abusers. Theses guys are likely going to die of abuse related illness but my goodness their organs sure do work well.
To say they are harmless would be irresponsible. For my liver I have evidence that it works pretty damn well. Those AST and ALT numbers are actually a couple points lower than baseline.
Years before I was a abusing the hell out of my body drinking 12 to 18 ice beers several days a week with the occasional pint or 5th. That went on for about 2 years solid where before it was only weekends for the previous 5 or more years.
Then the years of crystal and cocaine abuse in my twenties that accompanied the usual weekend binge drinking. Oh let's not forget the 20 year weed habit and the occasional opiates. Ever see the color of ones urine after tweeking on an 1/8th of meth for 6 days? Liver and kidneys should have failed.
Why do some suffer ills from liver toxins and others not? I don't know. It's certainly not because I'm virtuous