Do not believe it.
It is not possible to earn $1000 or more using free money. That guy is lying or he might have invested his own money and created the impression with his friends that he is playing with free money.
Yeah, it is hard to believe that he won that much money by only playing free plays. Unless he can show us some proof of his withdrawal that can prove that he actually win using free money and not invested his own money to win that much.
According to the data on the network, poker stars held a million dollar freeroll in 2016.
Win your share of $1,000,000 for free
We’re giving away $1,000,000 in the next $1 Million Poker Freeroll - one of the biggest free-to-play poker tournaments ever hosted - and all real money players are invited to take part.
The latest $1 Million Poker Freeroll takes place on Sunday, October 9, and will award a staggering $1,000,000 - including $10,000 for the winner.
https://www.pokerstars.com/poker/promotions/one-million-freeroll/?no_redirect=1