The breach of trust inherent in text messages Pietersen is alleged to have sent to his South African opponents during the recently completed Test series, among a myriad of other issues, forced the batsman's removal from the England dressing room. Arthur, a former coach of South Africa, told ESPNcricinfo that in the circumstances England's selectors had no other choice but to drop Pietersen.
"It takes time to mend," Arthur said of the rift between player and team. "They say trust and reputation takes a year to two years to really build, and you can lose it in two minutes. I think that's where they've got to with KP now.
"England have dealt with it in the best possible way. The way they've handled it has been clinical, its been ruthless, it's been very good. It did obviously upset their team a bit, but little Jonny Bairstow came in and got 95 and 54 at Lord's and played really well, another guy steps up to the plate and does the job.
"There's no one guy that's bigger than the team and England must've thought that KP had got to that point. It was tough for them, it was pretty unsettling, but I think they've handled it very well."
Arthur was a bleary-eyed spectator for the Test matches in England, watching the matches on television in his Perth home. He was not surprised by the success of South Africa's bowlers in tucking up Andrew Strauss and Alastair Cook from around the wicket, but also lauded Vernon Philander for his adroit use of new-ball swing.
"I know from our last meetings with Cook and Strauss in 2008, we certainly came around the wicket to them," Arthur said. "Morne Morkel has been the one who has created a lot of problems from around the wicket, and that is certainly a line we'd explore to attack [against England]. What Philander did was he swung it, and anybody who swings the ball is going to be a handful.
"You want to try to play with the batsmen's feet, that's why you need to use your bouncer well, use it intelligently, that type of stuff. South Africa definitely did it very well."
Arthur's team are scheduled to be South Africa's next Test opponents in three home matches at the outset of the Australian summer, a prospect now rich with meaning since the winner of the series will be able to lay claim to top spot on the ICC's Test rankings.
"It looks like being another Test championship series and it is a mouth-watering prospect, certainly one I'm really looking forward to," Arthur said. "Our Test side's a really settled unit, to beat South Africa now you've got to play really disciplined cricket for a long period of time and hopefully we can have the preparation and be ready for that when the time comes.
"I know from our time together that the South African guys are a resilient bunch, they enjoy touring together, they're a really good team, a good team ethos going, they're well-led, and very well coached. I think they all believe in their ability now, they believe in their ability to win the big games, and I can't wait for that Test series [in Australia]."
In the meantime Australia have 50-over and Twenty20 assignments in the UAE and Sri Lanka, with Arthur leaving the ODI leg of the tour to his assistant Steve Rixon. Rather than marshal the team against Afghanistan and Pakistan, Arthur will be tuning his plans with George Bailey for the World T20, particularly the nuances of the Premadasa Stadium in Colombo where the Australians will be based for the group phase.
"I'm just clearing my head and getting a good idea in terms of the roles we want to use for players," Arthur said. "There will be a bit of opposition analysis in that, and just getting a real clear head around the way we want to tackle this, have a look at how successful teams have played at Premadasa, study that ground a little bit. I'm suspecting towards that back end of the tournament that the wickets will turn, so I'm just getting all the attention to detail right."
Daniel Brettig is an assistant editor at ESPNcricinfo. He tweets here