Out of interest, let's try removing the weather from the equation and imagine that it was a gin-clear day, and let's suppose that an eye witness saw the whole thing.
He/she described the aircraft rolling very slowly to starboard at about 400 ft until, having passed 90 degs of bank, the nose was dropping below the horizon, rate of roll increased somewhat and the aircraft rolled almost all the way round, nose dropping all the time. Eventually, the nose started to rise, but it hit the rising ground, still sinking, with the nose above the horizon and a few degs of left bank.
What would your hypothesis be regarding the cause of the crash? Unauthorised aerobatics? (In a Chinook?!)
Would you reach for the 'Grossly Negligent' rubber stamp?
Or might you wonder if some unknown unserviceability had led to a loss of control leading to a loss of several hundred feet of altitude and catastrophic impact with the ground?
Remember, you have no ADR and no CVR. Oh, and the Chinook is known to suffer from electrical and mechanical disconnects within the Flt Ctrl system, spurious engine faults caused by immature FADEC software and prone to UFCMs.
Any doubt whatsoever?