Statistical evidence is a form of scientific proof.
At this stage in the debate, with the number of people who have participated, and the number of kills we would have collectively had, the fact that no one has as yet been able to link to an armory profile with the mount is compelling.
Although this does not represent absolute (100.000000000000000000000000000000000000%) certainty, it makes it a lot more certain than many things we take for granted in life.
At this stage I would say it is likely they are looking into it. Hopefully they'll give a reply soon. I am sure that none of the devs realised this was a case, and until now they would have had very little reason to think anything was wrong.