This assumes the researcher is indifferent to white/black hatting. In all likelihood, the researcher may have some personal preference to be a white or black hat, and it could depend on the ethics of the company in question.

There is also the cost of the likelihood of being caught while selling vulnerabilities on the black markets. If fascists have some personal stake in the company, black hatting would likely involve more careful and high stakes anonymity measures. Remember that US federal law enforcement agencies operate tor exit nodes!