I actually had this quoted to me in a domestic airport. I was checking in on an AA flight (I believe Boston or Manchester to DFW.) My plan was to check in and drop my bags then drive the rental car to have some lobster and then fill up the car and come back... I knew due to status they'd take my bags early... They did, until I casually mentioned my plans. The agent said "I wish you hadn't told me that..." And then explained (I can't remember if she said it was policy, a rule, or law...) That if I left the airport they couldn't keep the bags... It was a little frustrating, certainly inconsistantly enforced, and silly... But I didn't fault her... I just took my bags to lunch with me and did it all when I got back...