My theory: Dorian thought the reporter was asking him about his past at the defense contractor. Doing work for a defense contractor sometimes gets you crap, so maybe he was trying to distance himself from that, like, "No, I used to work for a company that did potentially evil for the government, I'm no longer involved with it". I know some people who did work for defense, and they're not very open about it.

The reason why he thought the reporter was asking about his work at a defense contractor vs. bitcoin? Plain ole' miscommunication... Leah perhaps presented herself in an unconfident, possibly suspicious manner like she's out to get him and the guy's like "nope, not gonna get into this". And to be fair, English is this guy's second language.