It's one of those tape collar-seals breaking spontaneously, at which point the hung reel falls to the floor and takes off across the room, generally unwinding the tape as it goes.
If it is generally UNwinding the tape as it goes, the reason is exactly the same as why buttered toast always falls buttered side down:
It is NOT due to the aerodynamics during the fall.
It is NOT due to the center of gravity.
It is because you are winding it the wrong way around - (or
buttering the wrong side)
