A brick layer who notices the wall falling apart and keeps building is doing it for several possible reasons, here are the two major ones I consider:
1) Fraud - they want to get the wall built, be paid, and get the hell outta Dodge before someone notices (Malicious intent)
2) Incompetent - they don't notice the wall falling apart.
3) Directions - their boss tells them to keep building despite the bugs.
If #1 applies, the boss is to blame for hiring the guy/gal and not monitoring the work quality.
If #2 applies, the boss is to blame for hiring the guy/gal, not monitoring the work quality, and giving the employee work beyond their skillset.
if #3 applies, the boss is to blame for ordering the guy/gal to keep developing despite the issues occuring.
In each case, you'll notice the Boss exists to provide direction. If the Bricklayer doesn't have a boss, then, yes, they are to blame. If the Bricklayer has a boss, the boss is to blame.
Authority is responsible when subordinates screw shit up.