My brother and his family had an old cat. This cat had problems with little children trying to grab it. It wasn't long before the cat's defending itself by scratching earned a last trip to the vet's office.
To me, a parrot with a sharp beak is dangerous when spooked. It can fly into a window trying to escape and get injured. A parrot can fly onto a guest who's not used to birds, and get batted away in fright...perhaps to be injured. A bird can bite a person, attacking a threat it sees or merely trying to get a steady perch on a human being.
Come to think of it, my Goffin's cockatoo has bitten me while perched on my shoulder--once because I was sticking my tongue out at it, playing a game that ended with the bird biting me on the lower lip, trying to get at that tongue. The bird has bitten my hands, too, not happy to be entering its cage.
Though I do leave my parrot out on a perch in the computer room, unsupervised for short periods of time, the door is shut to prevent a dog from entering and scaring the bird. Otherwise, I would never leave this bird in a room unsupervised. Too many accidents could happen--a doorbell ring, some shadow over a window, a strange noise from outside or inside the home, and so on--as the bird is startled. A scared parrot can't be blamed for injuring itself or people.
I'm sorry Ajay was scratched on the face by Mr. Lola and happy the injury wasn't worse.
Mary Jo