Example with a context (How Putin could lose power):
However, the very fact that the West and those Russians in the know were alarmed, and that even the Kremlin apparatus seemed clumsy and unsure of what to do, stress the degree to which if anything happens to Putin the regime will be in trouble — and we do not know what would follow.
What is the subject of this sentence? To me, it looks like the very fact should be the subject. Thus, we need a singular verb to go along with it. But, as you can see, that's not the case at all. The verb is stress and it is a plural verb. On the other hand, that entire monstrosity in bold might very well be the subject, although, to me, that doesn't really sound like it can be one—it'd grammatically inconsistent to think of it as the subject. Hmm, am I missing something here? What do you think is going on?