The bottom line is that there was uncertainty that couldn't really be disentangled from various other Boeing issues over the past couple years. As a result, eve

The bottom line is that there was uncertainty that couldn't really be disentangled from various other Boeing issues over the past couple years. As a result, even if nothing happened there would have been no shortage of criticism that NASA was behaving recklessly so the rational behavior was to proceed in the apparently prudent manner.