Nope, not touching the GPU, just spamming the CPU.
That is interesting isn't it. I wonder how the temperature sensors interact with the fan then. Although looking at power consumption of the 2, the i7 is 47W including the integrated chip if that is used, vs the nvidia GPU which is 75W. Although the GPU is closer to the fan and so has a smaller distance for the heat to travel, the CPU would still dissipate heat well. Also if you switch the the dedicated gpu, the integrated i believe would be inactive thus lowering the power requirement of the cpu too and also lowering heat in theory depending on auto-overclocking or turbo boost.
Could you share the temps next time you do this/see this happen? I would like to know how the temps of the haswell i7 compare more for interest than anything else