Quote from aerobat77:
"raising flaps immediately after takeoff will result in an crash very close to the airfield or a none event "
Sadly, the aircraft did indeed come down close to the airfield. Flaps and slats do not retract instantly.
Fortunately for the investigators, loss of thrust or any other fault leading to loss of performance (other than structural failure) should be recorded. A severe nocturnal tailwind-sheer seems improbable, but if applicable could also be inferred from the flight data.