Collaborative video annotation (CVA) combines media affordances to support critical thinking. A discourse analysis of preservice teachers' annotations in the process of a video-mediated observation of expert teaching revealed that critical judgements co-occurred with higher order thinking (HOT); however, criticism correlated less often with HOT than positive judgements of expert teacher practices. One hundred forty-one learners' small group discussions in CVA showed HOT annotations devoid of all judgment were the most frequent, and of HOT annotations that did contain criticism, applications of knowledge co-occurred most often with critical judgments, while analysis co-occurred most often with positive judgements, and intellectual modesty with mixed criticism. Results suggest that designs aimed at supporting critical thinking might benefit from expanded explanations of the purpose of observations and scaffolds to support the withholding of criticism.