I had a very similar situation. Dropped a few month old IPhone6 out of the hand onto the ground (concrete). The IPhone6, even being in a protective casing, fell face forward onto the ground and the screen cracked (fully functional otherwise). I did go into my local Apple retail shop and asked for options to get the phone replaced/repaired. The phone was inspected and the technician decided that my Iphone6 had not only a cracked screen but also was bent (Test via laying on a table on its back surface and if it spins its bent.) He also suggested that my story can't be true as a IPhone6 can't bent from a simple fall and even if he knows not what happened to the phone I must have severely abused it. He then issued a replacement ($409AUD). I felt not only treated as a liar but also shocked that such a simple fall could cause the IPhone6 to bend.
The next day I had a software related fault and had to ring Apple on their customer care number. While the customer care representative and I went through the process of resetting I briefly explained my experience the day before and was told that unfortunately this case (IPhone6 replacement was closed) but having this or a similar issue in future the customer service phone contact would handle cases like this with more sensitivity and based on my explanation only a screen repair charge might have been appropriate (approx. $160AUD).
So it seems that it depends on the technicians valuation and his feelings/your face what the charge might be from no cost to screen repair or full replacement. In the end of the day the phone is replaced in any circumstances.
