There's no reason for this guy, during his morning, night and afternoon routine, to be checking the writ delivery boxes this often. I am not sure what his deal is, but he's blocking the crates and your character can't properly interact. He could easily "inspect" them from a bit further back or just give up altogether, he's to obsessed with them.
I can't be the only one thinking this since the guy gets assassinated quite often, but then he's back patrolling the crates with his body double laying on the floor. I guess he never learns, inspecting those crates must be too important.