There were calls for a change in the law after England batsman Buttler, playing for Rajasthan Royals, was run out at the non-striker's end by the Kings XI Punjab and India bowler.
The method of dismissal is legal but one seen by many as going against the spirit of the game, at least unless the batsman had been persistently backing up and thus warned by Ashwin first.
The incident was all the more contentious as Buttler was still in his crease when Ashwin arrived, only for the bowler to pull out of his action and wait for him to step forward before whipping off the bails.
In a statement cricket's lawmakers, the MCC, have sought to clarify law 41.16: Non-striker leaving his/her ground early in relation to the Buttler controversy.
It said: "This law is essential. Without it, non-strikers could back up at liberty, several yards down the pitch and a law is needed to prevent such action.
"The crux of the issue is when the non-striker can safely leave his/her ground, and what the bowler can do to effect this form of dismissal without courting controversy.
"To clarify, it has never been in the laws that a warning should be given to the non-striker and nor is it against the spirit of cricket to run out a non-striker who is seeking to gain an advantage by leaving his/her ground early.
"Some feel that Ashwin delayed his action to allow Buttler the chance to leave his ground and that Buttler was in his ground when he expected the ball to be released.
"If it was a deliberate delay, that would be unfair and against the spirit of cricket. Ashwin claims this not to be the case.
"The TV umpire had to make a decision and, under the law, it was understandable how he opted to give Buttler out.
"It is up to both teams to ensure that the game is played within both the laws and the spirit of cricket.
Michael Vaughan, Eoin Morgan and Paul Collingwood were among those who criticised Ashwin's use of the 'Mankad', named after Vinoo Mankad who ran out Australia's Bill Brown during India's 1947-48 tour.