Accidents and mistakes can happen with this type of research, even with high level security procedures in place. In 2007, foot and mouth disease virus was accidentally released from a laboratory in the UK. An economically disastrous outbreak in UK cattle ensued. Because the UK is an open society, a thorough investigation was conducted and determined the source of the outbreak.
Dr. Anderson’s perspective, while valid and deserving respect, is circumstantial and probably naive. As a foreigner, she would be kept away from sensitive research. The notion that SARS COV2 made the leap from animal to human and was highly adapted to spreading exponentially in its new host is possible, but is also highly unusual. Thus, we have scenarios that are unlikely but possible, and one of them actually happened. My vote is on accidental lab escape.