What went wrong with your au pair?

[Anonymous]

Hm. I was on the spectrum and undiagnosed when I was an AP. Today I would probably have been diagnosed at school but 20 years ago? Naaaaah. Especially not outside the US. Today,my physician basically shouted "Asperger syndrom" at me when I just mentioned it. However, I am extremely well trained (I suspect my mother might be on the spectrum as well, we share a few... odd characteristics, to put it mildly). Yes, my life is a never-ending theater play but with the possibility for a bit of space to recharge my batteries I am fully functionable in the world, especially when working with children. I am actually a much worse HM than AP.

We have had better and worse APs. Our problems mostly stem from misrepresentations. On both sides.
When we first matched we presented ourselves as the family we wish we could be but we aren't (we would love to play boardgames together at night or do puzzles... unfortunately, mommy falls asleep before that). We changed that when matching with AP2. We are not the family we wish we were, we don't spend as much time together as we should, mom is odd, dad is not funny, everybody is crazy. We will include them into our family life as much as they want to but are unfortunately amazingly boring people.
For the applicants we take everything they say with a grain of salt. A 19 year old with 7 years of child care experience and a 7 year old sibling... yeah, we do not consider playing with your younger sibling after school child care experience. A 20 year old with 11,000 hrs of experience? Say what? That's a full-time job for five years without any vacation taken? May we doubt that (especially if you have just told us you went to school until you were 18 and are currently at studying something that is not child care related)? We expect the worst, hope for the best and match for personality, intelligence and roommate qualities... everything else can be learned. If they are smart enough.

The worst matches I have experiences came from misrepresentation or people not thinking clearly about their capabilities or needs. Again, on both sides.
I have met families who hired an AP to watch their (6'4, 250 lbs) 14 year old so he wouldn't pyhsically hurt his younger sister which basically meant not taking an eye off him. Ever. The boy held the AP and his sister at knife point, mommy shrugged it off, LCC said it could be worse, at least she was only working 25 hrs each week.
I have seen privacy being an issue. For both the AP (with kids or parents walking through their private space constantly) and the family (you are never. alone! there is always that foreign 20 year old who knows everything, some seem to be psychic, I swear... and they WILL tell their friends).
I have met APs who thought 45hr weeks with two toddlers (plus older, middle- and high-school aged siblings) would be an easy gig. When mom came home for lunch the kids (1 and 3) were playing in the living room alone, mom fixed lunch, sat down, AP came downstairs on the phone 10 minutes later. One month in. That was right before she didn't pick the 12 y/o up from baseball practice and left for coffee with a friend without him being accounted for.
There is personality issues, cultural differences, religious aspects, personal hygiene, roommate, language, driving... and living under one roof with (a) stranger(s) in general.