1
general::
Phrase(s): drive a coach and horses through something
Fig. to expose weak points or "holes" in an argument, alibi, or criminal case by [figuratively] driving a horse and carriage through them. (Formal. Emphasizes the large size of the holes or gaps in the argument.) • The barrister drove a horse and carriage through the witness’s testimony. • The opposition will drive a coach and horses through the wording of that government bill.
McGrawhill's American Idioms And Phrasal Verbs