As a layman I would argue that 2) is a better outcome that 1) since if 1) were to be true Idenix will likely have a hard time partnering with companies looking to combine treatments. If 320 was the sole culprit then obviously 184 will be in the clear and could be partnered at some point. Else companies will likely be nervous about both 184 and 320 since combo treatments are the future.
Actually the best outcome is that all 3 SAE's were caused by external factors and not by any of the 3 factors you wrote about but perhaps the likelihood of that is tiny.