Mistakes were made

"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. The acknowledgement of "mistakes" is framed in an abstract sense, with no direct reference to "who" made the mistakes. A less evasive construction might be along the lines of "I made mistakes" or "John Doe made mistakes". The speaker neither accepts personal responsibility nor accuses anyone else. The word "mistakes" also does not imply intent. 
"The New York Times" has called the phrase a "classic Washington linguistic construct." Political scientist William Schneider suggested that this usage be referred to as the "past exonerative" tense, and commentator William Safire has defined the phrase as "[a] passive-evasive way of acknowledging error while distancing the speaker from responsibility for it". A commentator at NPR declared this expression to be "the king of non-apologies". While perhaps most famous in politics, the phrase has also been used in business, sports, and entertainment.
Despite some mockery of the phrase, its use is still widespread, and in the opinion of one commentator, "the type of evasive and corrupted language for which Ron Ziegler was repeatedly pilloried for using as Nixon's press secretary is not only accepted, but heartily and shamelessly embraced as a norm of political and social conduct."
Parody, comedic, and other usages.
An early parody of the phrase appears in Matt Groening's "Life in Hell" cartoon strip. Groening draws a looming shadow of the rabbit named Binky, towering over his one-eared son, Bongo, who has clearly made a total mess of the house. Bongo uselessly says: "Mistakes were made."
Playwright Craig Wright wrote a 2006 episode for ABC's drama series "Brothers & Sisters", called "Mistakes Were Made, Part One" (with Jon Robin Baitz). He expanded the gag into a one-man play starring Michael Shannon, "Mistakes Were Made", performed off-Broadway in 2009, to mixed reviews.
The phrase was also used in the multiplayer portion of "" to refer an un-natural player death not involving homicide, usually in the cases of suicide, accidentally falling to one's death, or being crushed.