The phrase "extreme mistake" is correct and can be used in written English.
It is typically used to describe a mistake that is significant or serious in nature. Example: Her extreme mistake of leaving the door unlocked led to a robbery in the house.
The foul is ignored by referee Ioan Igna, leading to BBC co-commentator Jimmy Hill calling it "an extreme mistake".
Referee Ioan Igna chooses not to give a free-kick, leading to BBC co-commentator Jimmy Hill calling it "an extreme mistake".
Know the difference, or you could make an extreme mistake in building a career around a fantasy rather than around your innate strength and sense of purpose.
"While Flint's case appears extreme, make no mistake about it: Lead-contaminated tap water is a national problem," the report says.
"Guillermo took responsibility for his actions and expressed extreme remorse for his mistake," General Manager Omar Minaya said in a statement.
Yet the film is an extreme example of the mistake most commonly made in adapting James: raising every subtlety to a literal level.
They often demonstrate a single-mindedness that borders on the obsessive and a social awkwardness that can easily be mistaken for extreme discourtesy.
King is so revered in our time that it's easy to put the spying on him and his colleagues in the box of mistakes so extreme that they are barely worth talking about: the N.S.A.'s practices may put one on edge, the argument goes, but it's not like people in the agency are sitting there trying to get a great man to shoot himself.
A British fancy fish tells them about the Drasticals, and because he spoke in lisp, they have mistaken for "extreme spots".
Social anxiety can be mistaken for extreme shyness or introversion, and about one-third of those with social anxiety are thought to go undiagnosed for 10 years or more.
Though it is only about 55 feet (17 metres) high, the formation is difficult to climb because of its extreme pitch and because a mistake would be deadly.
