There was also a third forum user,
Kryptoverdienst, who had only made a single post in the 'big wins on FreeBitco.in' thread over 4 years ago. His account shows he logged in a few days after winning the prize, I'm guessing he was probably getting a bunch of email notifications from forum users trying to message him.
I wasn't aware of the other two forum members who has won the Lamborghini from Freebitco. User 'fbtclam' had won it from the second round. 'TheQuin' said that he is an active member of the forum who used newbie account to hide his identity. And user 'Kryptoverdienst' has won the Lamborghini from the 5th draw. He is a newbie user who has made only one post about his $20 faucet win. The latest winner, 'soslex' is quite active in Freebitco thread. Therefore, we have seen 3 Lamborghini winners in bitcointalk forum out of the 7 winners. That's quite surprising.