Sizes differ from company to company even if they state they are the same size. Some will run smaller, some will run larger. Most of the time the rule of thumb is to get boots a size smaller than your street shoes (if they actually fit on your feet correctly). You want your boot to be tight, but you must also remember that they pack out which is why people downsize as much as they can handle. If your buddy had been riding them for awhile they could of easily packed out 1/2 a size or so, and the fact that they are made my different companies (which do have size differences sometimes) could easily make that boot fit you perfectly. Not crazy at all IMO.
Thank you for the info. I am hoping that now that I can fit these boots (and feel I can comfortably go a half size or full size smaller) I will no longer be stuck riding wide boards and hopefully open up the market a bit more for me.