Just ran into this, but one of the models went into T-Pose during their dialogue. I received a notification of an attitude change, the model started making his statement, and T-posed. It didn't look nature nor appropriate. Only happened for a second (before I could capture it). Best I can do is share a post T-Pose. 

I have also seen this occasionally during 4 playthroughs, and only with the leader avatar pictured in your image.