Irregardless
Apple's way of reporting sales is more accurate but a phone sitting in a carrier's inventory is a sale for the manufacturer.
Apple's is pretty much the same as everyone else's. I don't know how the rest of the industry handle's repairs, but Apple does count iPhone repairs and replacements as units sold.
Why does the OP care so much? Did Samsung fire you or something?
It's an ego thing for some. For others, it's like a sporting event. I like to cheer on a company every now and then and don't mind the drama of seeing the underdog succeed, but some just take this stuff too far.
I have no problem with the fact that companies massage their sales figures, TBH, it makes no difference to me, I don't have any shares, it is a part of business, most do it, I have no doubt that Samsung do, but on the other hand there's no doubt in my mind that so do Apple.
This sums up my opinion about the matter as well.