In the MyGM: The Saga Continues, eventually scouting reports will be leaked to another GM. When asked about it by the owner, say you want to have a TRIAL (but do not fire immediately.) It should pop up around June 30th of the offseason.
You will given the chance to question your staff. Go through the evidence accuse Lenny (since it was him) and then firing him, and later after Tex asks you about it after the fact a few days later (like July 2nd), the achievement should pop up.