This poses an interesting problem. This shows me that the group’s suggested actions were not clear enough, and the group needs to come back together again to further refine and clarify the actions. I would call a quick session for the group to do this — maybe 45 minutes. We would start with the actions that we finished the last session with, and show that the new problem is that the problem presenter does not feel they can take these actions on their own. This would hopefully lead to teamwork and delegation, or it would lead to a simplification of the actions.
One of the keys to Action Learning is the diversity of thought that the group brings to problem-solving. If one person does not want to participate, I would first try to talk to this person individually and find out why, and see if, as a coach, I can find a way to help this person see the value in their participation. If this does not work, I would look at the size of my group — if the group is big enough to move ahead without this person, I would do so, and ask this person to stay and observe so that they might better understand Action Learning and hopefully participate in a different session. If we do not have enough people to go ahead, I would have to cancel and find another willing participant.
This shows me the group is working really well together. I would let them work for a few minutes longer, and then intervene, asking them what they think the group is doing well and what the group can work on. This would allow them to focus on their building questions, followed by a clear look at what everyone thinks the problem is. Hopefully the build of questions is getting everyone on the same page about the problem and this intervention will help them see that.