The implication seems to be that martha is the leader here. However, consider a situation where all four members behaved exactly as Martha, staring at the printout for an hour in silence, looking for the solution. In this hypothetical, Martha still gets the answer first.
In that example, it seems pretty clear that Martha was not the leader, since they all behaved exactly the same; she was merely the strongest individual contributor. It seems like that's probably the case in the blog post example as well, since Martha's behavior is the same.
This post seems to be pushing the idea that the loudest and most social person in the room is not necessarily the best leader, which I can agree to. However, it also seems to be saying that the person who contributes most directly to the solution may be the leader, which I'm not sure is accurate. In a situation like the one described, it seems like the best leader would be the one who best facilitates the performance of the individual contributors- that is, leaves Martha alone.