Fig.: to find mistakes in something that someone has done or said

My teacher said that my written report was very good, but he picked holes in my oral presentation because it was too plain

Il mio insegnante ha detto che la mia relazione scritta era fatta molto bene, ma ha trovato da ridire sulla presentazione orale perché troppo superficiale

After the last terrorism alarm, analysts pick holes in airport security saying that new technology in screening passengers and luggage is needed, because metal detectors and X-rays don't cut it anymore

Dopo l'ultimo allarme terrorismo, gli analisti hanno trovato da ridire sul sistema di sicurezza degli aeroporti, dove - affermano - metal detector e raggi X non sono più sufficienti per vagliare passeggeri e bagagli, ma bisogna applicare nuove tecnologie

In this expression pick is used in the sense of pierce or poke, which goes back to the 1300s. The phrase itself dates from the mid-1600s