Before revision: "Mistakes were made " is an expression that is commonly used as a rhetorical device, whereby a speaker acknowledges that a situation was handled poorly or inappropriately but seeks to evade any direct admission or accusation of responsibility by not specifying the person who made the mistakes, nor any specific act that was a mistake.
After revision: like you"Mistakes were made " is an expression that is commonly used as a rhetorical device, whereby a speaker acknowledges that a situation was handled poorly or inappropriately but seeks to evade any direct admission or accusation of responsibility by not specifying the person who made the mistakes, nor any specific act that was a mistake.