It seems like this is a people management issue, not a restrospective problem.
Let's first think from the Scrum perspective: as others mentioned, the Scrum Master should avoid the ceremony to go for aggressive or non-value-adding topics. The team itself can help on that, but the Scrum Master is the responsible for facilitating the ceremonies.
However, thinking on future ceremonies and team sinergy, this should be addressed for this team-member manager to check what is happening with this collaborator. The manager could schedule an 1:1 to get deeper on what could be disappointing this collaborator.