This sort of thing is known to happen from time to time:
How did they manage to "ogling her thong" when in the later they state "wore jeans, moccasin boots and a midriff-baring, satiny blue top"?
The waist on the jeans is lower than waistband of the thong when she bends over.
She was probably wearing the really low rider jeans, where if the shirt she was wearing was short enough you can see the top parts of the thong. Not very attractive at all but apparently trendy with the young ones.
This sort of thing is known to happen from time to time:
"whale tail" coming out the top of the low riders...
Probably not safe for work...
...scratch that...totally unsafe for work...good thing I'm in a cubicle...
http://whale-tail.com/vote/?id=1072