I agree that stress shows us who people are, but with an asterisk. I think most of us are a little more on edge, thrown off by both the change in our daily routines and the huge giant worries swirling around us. And that can tend to make us a little more irritable and short. That's definitely part of us, but it's not all of us.
OTOH, very serious stress -- like, say, if we're not just worried about the virus but someone we love is sick with it, or we're not just worried about the stock market but wondering how to pay rent now that we've been laid off -- triggers our fight-or-flight response and literally shuts down the part of the brain that is responsible for rational thought and self-control. So, yes, what that person does or says in that scenario can be a reflection of what they think or who they are, but they may not actually mean it. Have you ever had some sort of really uncharitable or evil thought pop up into your head, and you're horrified that you even thought that and then tamp it down and figure out a civilized way to express yourself? That's the kind of thing that people are saying and doing, because their inner ability to tamp it down is just flat-out gone. I guess you could say that's the "real" person. But all of us have that part, and we've learned to control it as part of living in civilization and getting along with other people. So, personally, I try to avoid being quick to judge people under stress, because I just imagine what people would think of me if my least-charitable thoughts popped out uncontrollably.