They won't compromise life-safety. They can't get occupancy approval without approval from the City Building and Fire Departments. Those are the two agencies responsible for structural and fire/ life-safety. Construction is usually behind at some point during a building project. If something doesn't get 100% complete, it's usually the type of things that most people won't notice: BSE systems not 100% programmed, parking space counting system doesn't work, etc. Technical things that, though they are a nuisance, don't compromise the intended use of the building.