T20 Blast and PSL enforce MCC's ruling on such reckless fielding behavior, while T20Is and IPL don't.
This happened after Brathwaite hit the batter with his throw and led to the on-field umpires awarding the opposition side five runs as a penalty.
The incident occurred in the 13th over of Derbyshire's chase at Edgbaston, when Wayne Madsen attempted to take a run but turned back quickly as Brathwaite picked up the ball in his follow-through. Then the bowler instinctively threw the ball to break the stumps but instead hit Madsen's bat handle, which deflected for overthrows.
Brathwaite immediately raised his hand in apology, but Madsen was unimpressed, immediately gesticulating towards the square-leg umpire, Ben Debenham, before taking the run.
Brathwaite was seen in conversation with the standing umpire, Steve O'Shaughnessy gesturing that it was not intentional. Brathwaite was ultimately penalized for a Level 2 offense under the MCC Laws pertaining to 'Unfair Play', and Derbyshire, on 111 for 1 at the time of the incident, was awarded five extra runs.
The wording of Law 42.3.1 deals with incidents of "throwing the ball at a player, umpire or another person in an inappropriate and dangerous manner". But the same rule is not part of the playing conditions in international cricket and other franchise T20 tournaments such as the IPL. This is only valid in T20 Blast and the PSL.
In international cricket, similar action would earn the bowler a demerit point along with a potential monetary penalty. In the IPL, a player would be handed a monetary penalty along with a code of conduct warning.
"The umpires deemed Carlos Brathwaite's throw reckless and that is what it was. I was in my crease and he didn't even look. I know it's a competitive game but if that had hit me on the back of the head, like the umpires said, there is real trouble. Because I was back in my crease before he had even released the ball, it was a bit reckless,” Madsen was quoted by ESPNCricinfo after the match.
Here is the video of the incident: