“Arnold says he’s “not proud” but “grateful for lessons learned” during the incident.”

I’m confused about what lessons Mr Arnold learned. 

I’m not a lawyer, so I’ve had to make assumptions that may or may not be correct. If my assumptions are  incorrect, I’m sure that someone here will step up to correct me.

I believe this is the “incident” referred to (scroll down the page);

https://www.osbar.org/publications/bulletin/08apr/baractions.html

I assume that Mr Arnold, being an adult, knew that it was wrong to give a minor alcohol

I assume that Mr Arnold’s many years of law school at least mentioned a standard of ethical behavior required to be a lawyer

I assume that Mr Arnold  knew that RPC 8.4(a)(2) (commit a criminal act that reflects adversely on the lawyer’s honesty, trustworthiness or fitness as a lawyer in other respects). did indeed apply to him

If my assumptions are correct, exactly what lesson is left to be learned?