This is probably one of the intermediate (last) ES -> Production units that did have the ES flag set, but sent to manufacturing as production units.
There should be almost no difference between such units and the production ones.
If you scroll down a bit in the CPU information and under "CPU JKT/IVT/HSW Features" see "CPU Stepping: M1", that should confirm it.
Please see more below, under the "CPU JKT/IVT/HSW Features" section - there should be another entry for stepping.
I think that should be OK.
You can try to explain them that this part was probably improperly marked as ES in the chip (such mistakes sometimes happen), but all other parameters of this unit are same as production ones.
It detects the ES flag, same as HWiNFO does.