I don't see why OS HR>0.8 is a big deal in this case. This is NSCLC against Tarceva not placebo. As long as stat significant, I really don't care if HR> or <0.8. Tarceva got approved with HR>0.8 against placebo.
Let's assume, for arguments sake, that the Phase III is a success with an HR <.80. What would you have to conclude about your analysis? In other words, if you turn out to be wrong, how would you critique your own analysis?