Answer:
The sentence is unethical if there is a clear responsability on the mistakes. If the mistakes were made, and no one can be truly held accountable for that, then, the sentence is not unethical.
Explanation:
For example, if the government is corrupt, and officials actively commit embezzlement, the phrase "mistakes were made" is unethical because it is diverting the personal responsability of the corrupt officials.
But if for example, there is a volcano eruption, and the goverment tries its best to avoid casualties, but because of some involuntary mistakes some people still die, the phrase is not unethical because the mistakes were not voluntary and the consequences of those were not intended.
