He was hoist by his own petard when his trap backfired.
hoist by one's own petard
idiomHurt or destroyed by one's own plot or device intended for another; "blown up by one's own bomb".
Origin
disputed originFrom the play Hamlet by William Shakespeare, see quotations.
The politician tried to smear his rival, but he was hoist by his own petard when the public found out he had done the same thing.
The spy, who had planted evidence to frame an innocent diplomat, was hoist by his own petard when counterintelligence traced the forged documents back to his own printer.
- 01
abound in one's own sense
To follow one’s own inclinations and opinions.
- 02
ace up one's sleeve
A surprise advantage of which others are not aware.
- 03
act one's age
To behave in a manner appropriate to one's age.
- 04
act one's age, not one's shoe size
Synonym of act one's age (“to behave in a mature manner; to avoid being childish”).
- 05
afraid of one's own shadow
Exceptionally timid.
- 06
air one's dirty laundry in public
To reveal one's sordid secrets to the public.
- 07
air one's dirty linen in public
Synonym of air one's dirty laundry in public.
- 08
albatross around one's neck
A characteristic, possession, associate, or previous deed that hinders one's ability to succeed.