Few months ago I also tried to use AA Lowest Price Guarantee Refund because Expedia was cheaper. I bought the ticket via AA Web, and proceeded to claim to refund process. Then came to realize (after further reading on FT) that AA codeshared flight are not elligible for the refund so I called AA Web immediately and explained the situation. I suppose Apollo was looking after me that day, AA Web canceled my reservation and refunded me 100%. I'd say the refund process works but you need to read all the very fine print.