Yes, a pilot can crash a plane without a bomb.
But there was a bomb on board this one. The fireball was seen by many. The belongings all have holes blown in them and are very jagged.
Check the ground crew!
My guess is that the fragmented bodies, belongings, etc., have little to do with the bomb.
My guess is that when that aircraft went into the 360 degree turn, its airspeed and turn resulted in G-forces so great that the aircraft disintegrated so violently that it had the same effect as a bomb.
Whether the black boxes had power to record what happened at that point, I have no idea.
Pure guess on my part, but I do know that aircraft of that type will exceed their maximum structural loads in a split second.
The investigation will discover whether the bombs effect was localized to the flight deck or whether it was large enough to cause disintegration of passengers and the main fuselage.