Different people have different experiences. Different people have different thresholds for trust. Different people have different prior experiences. Some people have witnessed and been harmed by more lies than others. What does or doesn't seem like an overreaction to you, me, or others is going to be different to one degree or another to every individual. What you judge to be a small inconsequential lie may seem like a much bigger deal to other people who have other experiences and viewpoints. That's why the mask lie was not merely silly, it was flat out idiotic. Those responsible, the liars, assumed that everybody else would have the same tolerance for falsehoods as themselves. That was a myopic assumption to say the least.

(I got vaccinated too, but I have no particular animosity towards those that haven't. They are, if anything, victims of the government's long history of being untrustworthy.)