You're reading a lot into what was a fairly simple scenario with no mention of what the topics were. It came across as being an informal meeting with no agenda,

You're reading a lot into what was a fairly simple scenario with no mention of what the topics were. It came across as being an informal meeting with no agenda, moderator or stated outcomes. About all we can assume from the scenario are the power dynamics. Alice spoke first which says it's either her meeting or she is the ranking person there - not Carol. If it was a meeting to address the potential critical failure of a system that Carol is the most knowledgeable about, then yes, she should speak up. It could be potentially negligent to not do so, but most meetings are not that.