The employee was exposed to another employee who tested positive for covid-19. They asked him to stay home with pay for 14 days and he came back to the building to protest, putting other employees at risk.
I agree that breaking quarantine is bad, but let's look at his side of this. Amazon has the ability to shut down any protest or picket by alleging that an attendee was sick, or that a strike organizer was exposed.
Corporate employees have never had more leverage than they do right now.