Well, I can't see the aft mountings in those pics, but the fwd ones tell a lot.
You can clearly see the outboard fwd mounting is intact, with its bushing still in place, whilst the inner mounting has sheared. This would tend to indicate that the outboard bolt had either not been fitted, or if it was, it wasn't locked and worked loose, eventually falling free. The torque of the engine at take-off power probably placed a high assymetric loading on the inner mounting, causing it to fail, allowing the engine to drop forward.
If I recall correctly, the rear mounting is nothing more than an alignment pin, which will have simply disengaged as the engine fell away.
The pilot did a superb job in handling this event, but with the benefit of some accident investigation experience, I'd have to say that poor maintenance procedures were directly, or indirectly, to blame for this.
If the airline has now gone bust, it may have been experiencing difficulties at the time of this incident, which usually leads to shortcutting in maintenance and training.