Research stresses the importance of social components in learning. The social contact with peers and tutors stimulates reflection and supports higher processes of learning necessary for the internalisation and application of new knowledge. However, merely proposing opportunities for interaction does not necessarily lead to fruitful discussion and collaboration. Social presence and facilitation are key concepts for successful mutual learning. Both are represented in Murphy's collaboration model; social presence forms the basis of collaboration on which discussions and co-construction of knowledge evolve. Facilitation supports the entire collaboration process. In this paper, an adjusted version of Murphy's model was applied to analyse 1085 comments shared in an online course between career practitioners of a public employment service. The results show that without a dedicated tutor, learners can still be involved in collaborative learning and co-construction of new knowledge provided that the topic under discussion is highly relevant and controversial. Learners themselves take over social presence and facilitation activities, but less frequently than when a professional tutor facilitates discussions. Ex post summative evaluation revealed that only a few learners applied the gained knowledge in the long-term. As comparisons with related research suggest, higher facilitation support leading to a higher cognitive interaction with the learning could have better supported the transfer to practice.