Does it matter? How is a random person on the internet sufficiently qualified to define theft in a complex domain like digital copyright and intellectual property? You don't have to be a lawyer to be skeptical of what someone says online.
My point is if they replied “yes” where would you be? It’s not inappropriate to be skeptical but asking a person for credentials online is next to useless.
Even if they were a lawyer, lawyers are frequently wrong in their interpretation of law, which is why they argue the relevant points in court, and a judge gets to decide which of them is right.
