User blog comment:ClariS/Unofficial PBE Patch Notes (1.0.0151)/@comment-4947142-20121102130608/@comment-5015210-20121106115651

^^Champions attack range and spell range are different. Take Lee Sins Q, he fires it from his hand which is not the same as his attack range which is calculated from the center of his model so his Q misses everything under his attack range. What Riot is doing is making skillshots start from the center of the champions model, pull them back a few units, depending on the size of the champion. Amumu has smaller hitbox so they had to pull Bandage Toss 50 units back, to the modelof his model. Technicaly the range is the same, it just wont hit as far becuase it is calucated from the center of the model.