Since you're taking their word for how much there was on the front end, and it's their job to know (counting twice), I think I'd have had to split the difference ($25) with them if they could convince me the $50 shortage in her cash drawer was due to my transaction. Evidently you didn't count with her as she went through the PILES of money.
Were you chatting with her when she was counting it? Or since counting is such a big part of her job, is she just in the wrong business? Maybe she was distracted by your tight jeans? Rugged good looks? Big Wad of Cash?
Cuz