Do you think that the legal system always gives justice correctly?
Not always, they could make a lot of mistakes too.
The legal system in Mexico does not always provide justice correctly, as the judiciary makes a lot of mistakes too. Esta bien mi amiga. Es necesario aclarar el qué, que, cómo y por qué - entiende? Introduce the topic for the reader. Assume they do not know the question or topic. I hope this helps!! :)
Yes, I know but my grammar is bad :( I always wrote mistakes but thank you very much for your help :)
It seems to me that the question, "Do you think...", elicits a yes or no response. So, I would make just a minor suggestion as follows:
No, not always. They too could make mistakes a lot.