Fired based on lies.

I experienced as a witness a terrible scene of absolute injustice in my work environment, with unfounded accusations/lies that led to the dismissal of an employee - with very good productivity rates in the part of protection-categorization-dispatch of biotechnological equipment, therefore there was no reason for dismissal other than personal expediencies-, without there being any named testimony for these categories. And all this happened, while it is supposed that the feeling of respect, equality, etc. is promoted in there.
The story begins 3 months ago and contains various unacceptable behavioral issues, from verbal violence, to an inappropriate/immoral proposal to the employee who was nevertheless fired when these statements came to light. Also, it can happen to anyone in there - even me (i.e. if someone, while bothering me, tells lies about me out of revenge for example - without me knowing - there will be pressure (obviously absurd) to fire me overnight by my same superiors who simultaneously rate me positively and supposedly promote me without SERIOUSLY looking into the allegations/accusations and the rest background?! Is it all allowed?