They feared the coroner would spot a flaw before the body was encoffined.
Tips
culture
仵 is mostly met today in 仵作, the old word for a coroner who examined bodies, familiar from period crime dramas. Its older sense is 'equal, well-matched'. It is also a surname.
午 supplies the exact sound wǔ. Its meaning 'noon' is unrelated; it works as the phonetic beside the person radical, and the same 午 gives 忤 (to disobey).