The world No 21 was also involved in an apparent disagreement with the watching public and received a point penalty for the second match running because of his on-court behaviour.
"You look at that match today and you think "wow, you have got a long way to go" and it's not about the tennis - it's more about him as a person, his attitude and his ability to move on from hard moments in matches, " Croft added.
And he was stripped of his first-round prize money, set to be $27,071, for not seeing a doctor after calling it quits.
Johnson, the officials and spectators on the outside hard court looked on in disbelief when Kyrgios decided enough was enough.
Combined, the fines totaled to more than USD31,000.
"Guys, I want to apologise to the fans in Shanghai and those that watched around the world on TV today", he said in a statement posted on Twitter.
"I've been battling a stomach bug for the past 24 hours and I tried to be ready but I was really struggling on the court today, which I think was pretty evident from the first point", he wrote. The tweet later appeared to have been deleted from his account.
He later blamed a stomach bug on his retirement but did not seek medical help on court and then defied ATP Tour rules by not undertaking a medical examination afterwards. Subsequently, Kyrgios was fined and slapped with an eight-week suspension by the ATP.
He has subsequently also withdrawn from the doubles tournament in Shanghai.
This is the second year in a row where Kyrgios has found himself in hot water in Shanghai.
Last year Kyrgios was suspended and fined more than USD50,000 for a freaky outburst which saw him throw a 6-3 6-1 match against German Mischa Sverev while asking an umpire, "Can you call time so I can finish this match and go home?"
He later added: "Exactly why I shouldn't come here".
Kyrgios won that match, eventually going on to compete against Rafael Nadal in the final.
But he seemed untroubled by the injury when they entered the first-set tie break, but like in the final in Beijing, his temper soon got the better of him, after he was angered by the unsettled crowd and the umpire.