Unprofessional contractor's can exploit these practices because they know that the engineer will be under pressure to provide sign-off at the end of the project. At some point mandatory periodic site inspections could be imposed by building dept's.
There is potentially significant torsion applied to the support beam at the line of facade, and the torsion is further amplified by the weight of the fascia. I'm liking the idea to frame beams/cantilever beams around perimeter of the external slab and then the external slab becomes a simple span...