This is also something that is misleading but still isn't a lie. Just because AT&T hasn't sold a phone yet does that mean that Samsung didn't sell it to AT&T? Apple's way of reporting sales is more accurate but a phone sitting in a carrier's inventory is a sale for the manufacturer.
This is true but if you are a shareholder, channel inventory is very interesting to you for a couple of reasons. First if sell through is not good, you may be facing a fire sales situation later and that effects the uptake of new products (HP TouchPad anyone?). This is clearly not the case for the S3 and Samsung.
The other big reason its interesting is end of life which impacts margins, unless that channel inventory is close to zero, mfrs offer unnatural margin sacrifices and programs which hit the bottom line negatively, all in order to pave the way for the S4 or whatever comes next.
One other issue is terms for the channel, some channel partners have very advantageous terms which effectively make an overstock situation a return in the making, Sarbanes Oxley kind of addressed this with revenue recognition rules for US companies, but many other markets do not have those rules.