Knowing someone had committed petty theft is at least a red flag. I can't blame an employer for considering it disqualifying when they have many equally qualified candidates without it. Even for a burger flipper, let alone a secret agent.
My parents used to love to tease me about the time I stole candy from the grocery store as a child. Is that a red flag?
Not really, since everyone has done so. Even you.
Not getting caught for it on the other hand could be a positive.
No, it's fact. It's part of learning and growing up. You never stole anything in your life, not a piece of candy, nothing?