Collapsing of parachutes as sport ?

[Jon]

Just a question out of interest,
I am reading about the air battles over Malta at the moment and have read on several occasions descriptions of fighter pilots collapsing the open parachutes of their downed enemies with the slipstream of their aircraft. It looks to have been done by both RAF and Luftwaffe fighter pilots and although the parachutes opened again it would appear a few aircrew died as a result.
I am not here to point fingers at any Nation and i am aware that all countries had aircrew killed whilst under a parachute by fighters but, this looks to have been a "sport" not intending to kill. I have not read any accounts of this happening over Europe, Pacific etc...

Were these accidents or deliberate?
Did this just happen over Malta?