The literary technique being used is irony, specifically verbal irony. This occurs when the speaker says something but means the opposite, creating a contrast between the literal and intended meanings of the statement.
Verbal Irony (A+)
The literary technique being used when the intended meaning of a statement is the opposite of what is stated is irony. Irony is often used to create humor, emphasize a point, or reveal a contrast between what is expected and what actually occurs.
Oxymoron is a literary technique that involves combining two contradictory or opposite words to create a unique and often humorous effect. Examples include "jumbo shrimp" and "deafening silence."
The opposite of a flashback is a flashforward, which is a literary or cinematic technique where the narrative shifts forward in time to show events that have not yet happened in the main storyline.
Flattery means to compliment. The statement is not intended to compliment, thus likely the opposite (an insult).
A null hypothesis is written in notation by using a a statement that is the opposite of what is intended to be found, for example the research will derive answers or needed statements that is different from what is intended.
A paradoxical effect is one that is the opposite of that which was therapeutically intended.
irony
A reaction that is the exact opposite of what was therapeutically intended is a paradoxical reaction.
Technique is a prescribed procedure; the opposite is hit - and/or - miss.
The negation of a statement
A statement which has an opposite opinion to a theory