A woman charged with running over twin brothers was either moving below the speed limit or had faster than average reaction time, according to a collision investigator.Tracey Pitt, 51, has denied six offences in connection to a crash on Woodland’s Road on January 29 last year which seriously injured 36-year-old twins Randolph and Rudolph Smith.Among the charges are two counts of causing grievous bodily harm by driving while impaired and one count of refusing to give a sample of breath.Supreme Court previously heard Ms Pitt admitted to officers that she had two glasses of wine prior to the early morning crash.And collision investigator Emerson Carrington told the court the victims were sitting, squatting or laying in the road when they were struck, but he was unable to determine how fast Ms Pitt was travelling due to the lack of brake marks.But taking the stand yesterday, UK forensic collision investigator James Keenan told the court he found several inconsistencies in Mr Carrington’s findings, including the distance that the twins were dragged by the vehicle.While Mr Carrington told the court the pair were dragged around 13.26m (43.5ft), Mr Keenan told the court the drag marks were actually 17.2m (56.4ft) long.And based on the measurements recorded by Mr Carrington, he said Ms Pitt’s car would have been in the northbound lane when it was actually in the southbound lane.“It also shows the length of the car as just over 3m long, when in fact it was 4.1m long,” Mr Keenan said.He acknowledged that there were no brake marks at the scene of the accident, but said the drag marks found at the scene, together with witness testimony, could suggest the speed Ms Pitt was travelling and her reaction speed.Mr Keenan said Ms Pitt’s recollection was that she felt an impact and then applied brakes, a version of events supported by witness Minh Do who testified he heard the collision before seeing brake lights.He said that if Ms Pitt reacted at average speed, based on the distance the vehicle travelled before stopping, she would have been driving at 27kph at the moment of impact.And if she had been driving at the speed limit of 35kph, her reaction time would have been 1.2 seconds — half a second faster than average.“If the reaction time was longer, then her speed must be slower,” he said.Looking a pictures of the scene of the crash, he told the court that while several pictures showed a street light illuminating the area, other photographs showed no ambient light, suggesting that the street light wasn’t lit at the time those pictures were taken.Under cross examination by prosecutor Nicole Smith, Mr Keenan agreed that he had not attended the site on the night of the crash, or any other time before last month, but denied the suggestion his findings were “guesstimates”.The trial is expected to continue today.