Complex sentence: If the bomb is live, there is a 50/50 chance that the photon took upper path, if, upon the wave collapse, it in fact took the upper path, than it "counter-factually" took the lower path (see figure 7).
Split into simpler sentences: If the bomb is live, there is a 50/50 chance that the photon took upper path. If it "factually" did so, than it "counter-factually" took the lower path (see figure 7).