The phrase "catch him out" is correct and usable in written English.
It is typically used to describe the act of exposing someone’s mistake or tricking them into revealing the truth.
Example: "During the meeting, she tried to catch him out by asking about the discrepancies in his report."
Alternatives: "trap him" or "expose him."
Did we catch him out yesterday morning?
He stayed one step ahead of any fixed position, so that no one could catch him out in it.
Liberals saw him as caustic and arrogant, and devoted much effort to attempting to catch him out in self-contradiction.
To catch him out, I tried two things - a simple nutmeg, cumin and peppercorn job, and a more complex vinaigrette: both were annoyingly successful.
The onus is on Iraq to disarm, not on the inspectors to catch him out; and if he maintains his refusal to co-operate, how will higher numbers help?
The suspicious priests keep trying to catch him out in a declaration of anti-Roman sentiment: Is it lawful to give tribute to Caesar or not, they ask — that is, do you recognize Roman authority or don't you?
I'm sorry," Mike, the con man, says to his mark Ford, who has caught him out.
She had caught him out in his desolation: they were strangers to each other; he might even be angry with her because she'd let him down.
Having partly succeeded him as the Washington correspondent of The Spectator, I caught him out making a slanderous allegation in print that was backed up, when challenged, only by an unimpressive piece of bluffing and blustering.
'I slept with him a million times.' Lest there be any doubt about their laddishness, he added that had Lennon had 'a little gay tendency', he would 'have caught him out'.
— and then suddenly she can picture him, tall and rangy in a swimsuit so tight you could see every crease and fold, the washboard stomach, hair that fell across his face like a raven's wing, Richie Spano, the wise guy, the joker, with his braying laugh and the look on his face when you caught him out that said, I am so far above this.
