I think there is a difference between a player doing it almost spur of the moment vs an orchestrated attempt to cheat.
What may save Smith is that he is not alone.
Some current SAF's appear a few times in the below and I remember de Plessis saying at the time of lollygate that the Aussies won't say much because they all do the same thing (tamper with the ball). One of the Paki's got done once with a bottle top also if I recall correctly.
Regardless it needs to be stamped out. It basically means they all cheat but lets see who can get away with it best. As someone else posted the way around this is a mandatory new ball every 30 overs but what a shame to change the game in this way.
Dirt In The Pocket (1994)
Mike Atherton held onto the England captaincy and avoided suspension but he was fined $A3,700. The young skipper was using dirt, taken from the pitch, to try to keep his hands less sweaty while working on the ball during a Test against South Africa at Lord's. The Forfeit (2006)
Eyes on the ball: Cricket umpires Darrell Hair, centre, and Billy Doctrove, left, examine the match ball with Pakistan captain Inzamam-ul-Haq.
Photo: AP
Pakistan refused to take the field after tea on day four of a Test in England following ball-tampering accusations levelled by umpires Darrell Hair and Billy Doctrove.
Hair and Doctrove called the match off, awarding England the win via forfeiture. It prompted years of inter-board spats over the result, Hair's capacity to umpire and the governance of the International Cricket Council (ICC). The Bite (2010)
Pakistan star Shahid Afridi was banned from two Twenty20 internationals after being found guilty of ball-tampering during an ODI in Perth. Standing in as skipper, Afridi was caught on cameras trying to bite and chew the seam. Australian accusation (2012)
Bowler's pick: Peter Siddle was accused of ball tampering by Sri Lanka,
Sri Lanka notified the umpires that they believed Peter Siddle had been attempting to raise the seam on his way to taking 5-54. He was cleared by the ICC over the incident. The Zipper (2013)
Faf du Plessis pleaded guilty to the charge of ball tampering and was fined 50 per cent of his match fee.
The South African rubbed the ball on the zipper of his pants pocket, prompting umpires to award a five-run penalty against the Proteas.
Team manager Mohammed Moosaje insisted it was "harsh" to call it tampering, while AB de Villiers insisted "we are not cheats". Not-so-subtle Scratching (2014)
South Africa paceman Vernon Philander was captured on cameras using his fingers and thumb to scratch the ball during a Test in Sri Lanka.
Philander dug his nails into the rough side of the ball. He accepted the charge and was fined 75 per cent of his match fee. Mintgate (2016)
South Africa enjoyed a crushing win over Australia in Hobart, after which footage emerged of du Plessis using a mint to help shine the ball.
The ICC vowed to investigate and du Plessis was charged with ball tampering.
Du Plessis maintained his innocence throughout a hearing and appeal but never managed to beat the charge.The skipper still has the resultant three demerit points on his record.