TL:DR: "My mac broke. I didn't actually bring it in to get it fixed, but fuck Apple for not fixing it anyway."
Besides the fact that transporting it could damage it further, he would probably would have just been told it was end of life or needed a new GPU altogether and the chances of them having said GPU in stock would be next to nothing.
Maybe it's just my area but Apple stores here do not actually repair products, they just tell you to buy a new one.
This is just silly - a computer is not a trauma victim, it's a piece of hardware.
My experience has been that they've spent two days isolating a problem on my 2005 iMac which I caused by using 3rd party RAM with the wrong timing - issue didn't appear well after I replaced the RAM (I replaced the RAM again, it worked fine).