A 27-year-old Victorian man has been arrested after allegedly following an ambulance to Royal Adelaide Hospital and threatening paramedics and a stabbing victim. The victim, a 32-year-old from Victoria, had been seeking help at houses with neck and hand wounds before paramedics transported him to hospital. Police apprehended the suspect on the South Eastern Freeway in a Porsche Macan, and authorities believe the attack was targeted with other potential suspects involved.