The white one is a static mesh exported from Maya while the yellow one is the skinned fbx file (with max influences per vertex of 6) imported into UE4 in the same pose. The difference is minor but annoying as it leads to unexpected dents on body surface. Any idea how to fix this? 
Upon further investigation I found that Unreal Engine reduced the per-vertex influence count to 4, this is getting more confusing as I remember that UE4 has support for a maximum influence number of 8 joints and will switch automatically. 