"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. The acknowledgement of "mistakes" is framed in an abstract sense, with no direct reference to who made the mistakes, or the nature and extent of the mistakes. A less evasive construction might be along the lines of "I made mistakes" or "John Doe made mistakes"; a similar active existential construction might be "mistakes happened". The speaker neither accepts personal responsibility nor accuses anyone else. The word "mistakes" also does not imply intent.