"Are you honestly arguing that a poster's choice of "an" vs "some" disqualifies his entire argument? "
Nope, he's arging that gp is lying about the situation, and thus is not credible.
Gp's claim is in direct opposition with OP's post, so he's either lying or ignorant, and neither makes him credible.
However, specifically op said he had TWO AMD 64 processors, which he used in a professional capacity,thud belying the assumptions made in gp's reply.
"However, a person is not a fanboi for pointing out obvious inconsistencies, regardless if he mis-remembered a not particularly significant number."
No, but their credibility suffers when OP says "I had two different systems, both of which I used in a professional capacity" which is what he DID say, versus GP's lie that he is" someone who tried an AMD CPU once, didn't do due their due dilligence, and just assumed all AMD procs were broken because their system was."
THAT difference IS significant, despite your clearly incorrect assertion that it isn't.
In short, you replied to something you didn't bother to totally understand and got it wrong.