No addendum necessary, they will see your transcripts, and even if they couldn't see this in the end all they really care about is that you were awarded a degree.
@splitter91 I think it was the first question in the section, a disagreement question about a guy having a lot of/too many traffic violations or tickets
I don't understand why you need to explain the first... It sounds so ridiculously minor that I've never seen an app that would require it. I'd send the LSAT addendum but I wouldn't send the other.
Oh, and don't mention that the professor who wrote you to the dean was a first year professor in your addendum though! While that provides context to us, I don't think admissions would like it. Just and FYI.
... require you to submit an addendum explaining what happened and how ... score, write an honest/ forthcoming addendum and watch the acceptances roll ...
It will hurt but you have to move on. You have to show them that it is PAST. Try to end your addendum with a positive note such as "After xxx, I finished school with a 4.0/4.0 GPA" or "I finished my last two semesters in college with straight A's."