I am not a security researcher, and I do not speak for the person you are replying to, but I do believe that Intel's documented history of unethical, anticompetitive practices against AMD, for example, deliberate compiler handicapping for non Intel CPUs[1], is enough evidence to establish at least some suspicion regarding these results, especially considering the short warning given to AMD before public disclosure.

I also wonder, what is the purpose of such white hat operations if vulnerabilities are disclosed publicly without anywhere near adequate time for a fix? Isn't SOP to give more time before going public?

1.https://en.m.wikipedia.org/wiki/Intel_C%2B%2B_Compiler#Criti...