Surgeons were forced to amputate Jonathan Wright's leg below the knee while Matthew Foley suffered a fractured leg after Jakob Thornton allegedly crashed into them in the city's southwest in February.

The senior constables had been setting up a random breath testing station when they were pinned between the car and a police van, and Thornton has been charged with two counts of dangerous driving occasioning grievous bodily harm.

The 22-year-old won his bid for bail in the NSW Supreme Court on Thursday when he appeared via video link from jail.

Thornton's mother Katja, who will pay a $5000 surety as part of bail conditions, cried in court as Justice Peter Hamill delivered his ruling.

Lawyers could barely hear each other talk above the constant screaming and hooting in the background from Thornton's prison room throughout the hearing.

"That sounds like a nice place for a young man to be," Justice Hamill said sarcastically.

A prison nurse said Thornton, who appeared exasperated, was displaying symptoms of PTSD, his lawyer told the court.

Justice Hamill said while Thornton has a "cascading" series of other driving offences, he has very little criminal history.

Although his serious charges usually result in a custodial sentence if convicted, the judge noted there'd be a lengthy period before his committal hearing with the police brief yet to be served.

The judge dismissed prosecution claims that Thornton may fail to appear when his matter is next heard at Campbelltown Local Court in May as Thornton doesn't own a car or a passport.

Thornton was allegedly looking at his phone for 10 to 20 seconds when he smashed into the two officers in Leumeah.

Court documents show Thornton couldn't remember whether he applied the brakes before he hit the officers at 60km/h on Campbelltown Road on the evening of February 16.

Thornton's provisional licence has been suspended four times and he was caught using a mobile phone while driving two years ago.

The NSW police union was left "devastated" by Thursday's decision.

"We had a police officer that has an injury for the rest of their life, they lost their right foot, but then again we see the offender that's out on the street," Police Association NSW president Scott Weber told reporters.

Mr Weber said despite the traumatic event the officers are in "good spirits", receiving overwhelming community support from ongoing fundraisers to cover their medical bills and assist their families.

Australian Associated Press