The Wanderers pitch has by no means given an all-clear even though the Test is set to continue after the umpires took the teams off 19 minutes before stumps on day three. The umpires will remain on alert for any other behaviour they might consider dangerous to the safety of the players.
The pitch has had extravagant bounce and seam movement throughout, but on day three the umpires were worried about players' safety. After meetings between the match officials and the captains, and possibly consultation with the ICC, the match referee decided to continue play on day four. ESPNcricinfo understands this was more deferring the decision to the next morning so they could sleep over the decision, understand the ramifications of it, including other sanctions and the fact that India had already courageously fought their way with the bat on this pitch, and hope the pitch settles down on day four. Despite all these considerations, the match referee will not compromise the safety of the players. If it continues to behave dangerously, the match could still be called off.
The officials could afford to buy the overnight time because they were losing only 19 minutes. There's no telling how it might have panned out if a batsman had been hit on the head at, say half past three and not 11 minutes before 5pm. The delivery that led to the suspension of play was a short-pitched delivery from Jasprit Bumrah, which hit Dean Elgar on the helmet, but the umpires had been concerned all day with balls rearing off a length and hitting the batsmen in the ribs, gloves, and thighs.
The first time the match officials spoke to the teams about the state of the pitch was during the tea break on day three. According to India's manager Sunil Subramaniam, the umpires' concern was that the new ball could behave dangerously. While India's second innings lasted only one ball with the second new ball, Elgar was hit four times in 8.3 overs of bowling with the new ball in South Africa's innings.
In the captain's meeting with the match referee, India - in a great position to win the Test and after having braved this difficult pitch - made it clear there was no way they wanted the match to stop. The South Africa manager said they told the match referee they were not going to comment whether the pitch was safe or not, but they were happy to play if the officials deemed the pitch to be safe. The eventual decision still rests with the match referee. There is provision in the law that they could attempt to repair the pitch, if possible, to see if the match can continue, but it can't be done if it disadvantages one of the teams, which in this case will be India's fate. So that route is unlikely to be taken.
The pitch has come in for harsh criticism from experts and former cricketers covering this series, with Michael Holding calling it a "s**t pitch", one he would rate 2 on 100.