As Kav says, Heuer was pretty liberal with the different case/hand configurations, so maybe let's not dismiss this immediately.
Let's try use the occam's razor method, as discussed in a previous post.

Two hypotheses:

1) It is a stupid put together

2) Sometime in the mid 70's, Heuer's design team decided to create a one off prototype of a new Autavia case. We need to ignore that the basic shape of the Autavia case stayed the same from the late 60's to the late 80's, but this was a super secret prototype. In this super secret prototype, the Heuer design staff, in a fit of anarchy (maybe it was 1977?) decided to randomly select non matching hour/minute, second and sub dial hands. Not only that, the designers thought it would look good if the dial was slightly off centre from the (non matching) tachy ring. Because it was so secret, they managed to hide it from every Heuer expert in the world, including people who worked for Heuer. To preserve this secrecy, the original design team are still locked in a secret vault deep under the alps.

I don't want to force people into any conclusions, so I leave it for you to decide which is the simpler and more probable hypothesis.

I understand the Antiquorum staff can't be experts in every single watch brand, so might miss something subtle like that the hands of a third execution Autavia are used on a second execution case, but this is just plain stupid. Even my ten year old son could have checked onthedash for 5 minutes and seen that no such watch could ever come out of Heuer. I think on vintage watch forum's across the internet watch obsessives are often to quick to jump to conclusions and are fussy beyond reason ("I have carbon dated the lume on the hands and it is 13 hours later than the dial, so I threw the watch away"), so sometimes I sympathise with Antiquorum but in this case I think they should be ashamed.