It would be almost certainly over-weight with 3 on board and full fuel (pictures on the Web show it parked outside - so maybe it still was and with full fuel to reduce the chance of water contamination). It will DEFINATELY be over-weight (and possibly uncontrollable in certain situations) with 3 on board if operating in the Utility category (that is, carrying out certain manoeuvres, such as spinning). There was another sad accident some years ago when two very experienced airline pilots and instructors crashed in the sea after spinning a -140 off the Fylde Coast. The aircraft was over-weight for the exercise and CG out of limits.
FlyingOfficerKite
I think and correct me if I am wrong but the 140 with a rearward C of G had a problem coming out of a spin.
This appears to be a high speed almost vertical dive into the ground which would not indicate a spin to the ground.
In a spin the vertical descent speed is relatively low and stabilises
Maybe an initial spin followed by a dive coming out of it or even a spiral dive but I would question this as a spin to the ground as it appears it was too fast and at very high speed.
Pace