"vanishing mother"

My 94 year old mum's Doctor arranged for an ambulance to take her to A & E with a letter for a knee x-ray as she'd had a nasty fall at home. I live and hour and half away so got to mum's house as soon as I could to find she had already been taken, which was good. I arrived at the hospital at 7.45, asked the receptionist where mum was she checked the computer and said quote "well she's not here and she's not in Wakefield so she may be still in transit - wait a few minutes and see if she turns up" so with that information I sat in the waiting room which was fairly quiet. Half an hour later and still no mum I rang mum's house and she was back at home. My concern is that the receptionist could not find a record of my mother on the system when in fact she'd attended, had an x-ray and no-one knew where she was which I find quite worrying.