Unintentional Mistakes DONOT requires disqualification!

I am late on this news but still, wants to highlight such things happening around. Novak Djokovic(No. 1 Tennis player in the world) on this sunday was disqualified from USOPEN due to a very strange reason, The person standing at the corner of the court "The line person" got accidentally hit by the ball , while he was looking the other way when he pulled the ball from his pocket and smacked it in the direction of the the line person, it hit her full toss in the throat. The official cried out and began gasping for air as she collapsed to the ground. Her struggle to breathe properly was clearly heard on the broadcast. But Novak seemed extremely guilty and ran towards her immediately apologizing and tapping her back to help her comfort.

I know it was indeed a bad accident, the lady could have suffered severe damage. But at the same time, Yes the punishment could have been imposed to Novak in the form of less severe than complete disqualification. I completely condemn over the decision taken by officials at USopen.
What's your take on this?