An air ambulance had to be called in after the smash at Auchenlarie Holiday Park, near Gatehouse, on Saturday.
The copter was used to fly two of the injured - including a woman in her late 20s from Newton Stewart who is a member of staff at Auchenlarie - to Glasgow's Royal Infirmary following the three-vehicle smash at 7.30pm.
A van and two cars were involved and the A75 was closed completely for several hours. Travelling in the van was a family from Creetown and a Spanish English language student who had been staying with them.
Incredibly, all those involved, including the woman - Marta Homeleva, who had to be cut free from the wreckage of her Audi - suffered only minor injuries.
The family were kept overnight at Dumfries and Galloway Royal Infirmary and discharged the following day, while the Spanish student who is in his early teens was not admitted to hospital. He was looked after by the organiser of the Spanish student trip.
Marta's workmates were overjoyed to be told she had escaped serious injury without so much as a broken bone. "Everybody here is delighted," commented a colleague. Marta, who is originally from Slovakia, started working at the holiday park three years ago.
Onlookers watched as fire and ambulance crew crews battled to free Marta. Mr Swalwell laid the blame for the accident at the door of the Scottish Government for forcing him to close one of the park's entrances, leaving just one on a bad bend. Traffic from the west now has to use the east entrance, cutting across the A75 on the bend where vision of oncoming traffic is extremely limited. "We told the Scottish Executive that this would be an accident waiting to happen," he said.
"In my 23 years at Auchenlarie, we have only ever had one serious accident and then, within six months of the changes we've been forced to make by the Scottish Executive, we've now got a member of staff and two other people in hospital. I am incensed."
Mr Swalwell, who received news of the accident while on holiday, said that he had applied for a further 31 caravans on the 400-caravan site, but claims he was told by the Scottish Executive he would not get permission unless the west-bound entrance was sealed off at a cost of £52,000, leaving just the east-bound entrance on a sharp bend.
Mr Swalwell said: "I take no satisfaction in being able to say to the Scottish Government I told you so.
"That bend is so dangerous and I want it known that Auchenlarie Holiday Park objected to what the Scottish Government wanted us to do. We were told that we would not get one more caravan on to the site unless we closed the west entrance.
"I was forced to spend £52,000 on altering the road and the result is I've got a member of staff in hospital."
Meanwhile, a spokesperson for the Scottish Government agency, Transport Scotland, said: "There will be a full investigation into the cause of the accident."