I was fired because I didn't remember the date of a speeding ticket I got in my personal vehicle on my on time?

I hold a CDL and drove for my employer. They gave all the drivers a driver safety course taught by an outside instructor. At the end of the driving cl the instructor ped out a PENN DOT form. He asked us to list any driving Violation from the past 12 months, sign the form and p them back to him. I listed my most recent ticket, signed the paper and ped it back to the guy. A week later my boss calls me in the office, shows me the form I filled out, and a copy of my driving record. They told me that I had a speeding ticket, on my own time and in my own car by the way, from 10 months ago that I did not list on the form That I had signed it and certified the info was correct. I told him it was an honest mistake that I just didn't remember the date of that speeding ticket. I thought it was over 12 months ago. So they fired me for dishonesty and their conduct policy for not listing the speeding ticket. How can I be expected to remember the exact date of a ticket from almost a year ago. Plus the guy had my driving record already so why am i being asked to write it down in the middle of a driving cl. Is this a wrong full termination? I had no time to call PENN DOT so I could get the correct info. The instructor gave us only 2-3 minutes to fill it out. Not to mention they already had my driving record.