My Daughters 9 year old friend..is this normal ?

My daughter just turned 9,she has a difficult time making friends.She made a friend that shares her quirks and they have playdates..etc..her family lives within earshot of our house...like a block away.Both have gone to each others houses without their respective parent tagging along for the duration.Sooo..my daughter had her birthday,and after being stood up by everyone invited last year we just decided it would be best for her and her buddy to do something together.We called her parents and asked if she could stay the night and go to the movies...they say ok..that it would be her first sleepover away from home.Then a few days later say that she has never rode in someone elses car for that long of a trip.If they could drop her off at the theater which is 25 minutes from home.So,we ask if she would like to come to..."oohhh no..that's ok I'm just protective".Soo they change their mind...they let her ride with us.OK..this is what I'm asking about...when the movie was close to being over I step out for a cigarette.I'm kneeling on the sidewalk up from the theatre.I look up and see her dad driving up the lot!!??I'm thinking maybe its not their car...but he drives right up to the door and looks all around,looks up and sees me a distance away,mind you....and turns down an aisle and gets the heck outta there!!So..I think. Maybe it wasn't him...then the next day when he pick her up he tells my wife...I was in the area yesterday....had an errand to run(in the same place we are at?)I saw your car"...???I'm thinking these people are CRAZY...I'm protective of my kids as well..but that is insulting...as well as a little psychotic IMO...stalking us on our 9 YO birthday?Is that normal or do I need to be worried bout them?