I hate the 'don't worry, he's friendly' which is exactly what the owner said to my son moments before it bit his face!
Same with me.
Was on college placement when I was 17 and was meant to be with a family with two young DC, went to meet them few weeks before hand they brought their Rottweiler out to "meet" me so that it would it know who I was etc, but not to worry as its friendly. They brought him out on a leash and it pulled Mum jumped up on me and had me pinned by shoulders on couch, it growling inches away from my face. I asked the parents to please pull it off me as I wasn't comfortable and was again told, it's being friendly, two seconds later, half of my tutors face was ripped off. I'm not exaggerating either. The skin from bottom half of her face was all gone.
They still didn't move dog out of room, their little DC were sat next to me, in hysterics, which was making the dog worse and trying to get at us. Dad eventually took dog out when I phoned ambulance and was told to ring police too. I gave tutor first aid, calmed the DC, while Mum and Dad still insisted it was a friendly dog!
I can't remember getting in the ambulance with tutor, she says I passed out. I was wary of dogs for a long time after that, strange knew would approach me and I'd get awful flashbacks the minute I'd hear "don't worry he's friendly". I used to explain why I was nervous thinking they'd understand and stop their dog jumping at me, but it didn't, they'd say I had to "face my fears" and continue to allow their dog to jump on me, trying to force me to stroke it etc.
I know how stupid I'll sound but it really affected me to the point I'd freeze if I saw an unfamiliar dog charging at me, I'd detour to avoid walking past an off leash growling dog.
I'm mostly fine now, only get flashbacks when I hear "don't worry he's friendly" from a growling dog's owner.