PVS-Studio warning V502 for UnrealEngine4

class FUniformExpressionSet : public FRefCountedObject
{
  ....
  uint32 GetAllocatedSize() const
  {
    return UniformVectorExpressions.GetAllocatedSize()
      + UniformScalarExpressions.GetAllocatedSize()
      + Uniform2DTextureExpressions.GetAllocatedSize()
      + UniformCubeTextureExpressions.GetAllocatedSize()
      + ParameterCollections.GetAllocatedSize()
      + UniformBufferStruct
          ?
          (sizeof(FUniformBufferStruct) +
           UniformBufferStruct->GetMembers().GetAllocatedSize())
          :
          0;
  }
  ....
};

This suspicious code was found in UnrealEngine4 project by PVS-Studio static code analyzer.
Warning message is:
V502 Perhaps the '?:' operator works in a different way than it was expected. The '?:' operator has a lower priority than the '+' operator. materialshared.h 224

PVS-Studio is a static analyzer for detecting bugs in the source code of applications written in C, C++, C++11, C++/CX. Site: http://www.viva64.com/en/pvs-studio/