What is a risk when a technical leader also serves as the scrum master?

The scenario where a technical leader also assumes the role of the Scrum Master can indeed lead to specific risks that impact the effectiveness of the Scrum team. When the Scrum Master also acts as a tech lead, there is a significant possibility that they may give too much direction. This situation arises because the tech lead, drawing from their technical expertise, may unintentionally influence team decisions and solutions instead of empowering the team to self-organize and arrive at their conclusions.

In Scrum, one of the vital responsibilities of the Scrum Master is to facilitate a team environment that promotes collaboration and autonomy. If the Scrum Master is overly directive, it can undermine the self-organizing principles of Agile. Team members may feel less inclined to contribute their ideas or take ownership of their tasks, as they may look to the tech lead for answers rather than exploring their solutions and sharing responsibility for decision-making.

While the other choices may present certain concerns in different contexts, they do not address the core risk associated with the duality of the roles in this specific way. This over-direction can restrict the development of the team's capabilities and ultimately hinder the Scrum process itself.