I think Figure 6 makes a very important point, but I think there's an error. First of all, it might be helpful to specify the ordering of the recombination breakpoints along the genome. I realize that they are indexed alphabetically in time, but maybe explicitly stating 0<v<y<w<x<m would be helpful for comprehension. Anyways, assuming that's the correct ordering, we look at the two lineages left at time T: {(x,m,1)} and {(w,m,2)}. Conceptually, this can't be the case, because a common ancestor event between these two lineages would still leave an uncoalesced (w,m) segment. Concretely, the (w,x) segment from the leftmost sample goes missing. At event b, we have {(v,x,1)} and {(0,w,2)} having a common ancestor event to produce {(0,v,2)} but I think it should produce {(0,v,2), (w,x,1)}, right? If this is the case, the RE column and part B would need to be adjusted accordingly. Let me know if what I'm saying here makes sense or not.
Pointed out by Andrew: