No, that he is whining. He isn't being questioned because of his name; he is being questioned because he is whining. The quip about his name is not an ad hominem because the quip is immaterial to the argument.
There is no "you should question this because his name is Foo", rather "you should question this because he is acting Fooish, which incidentally sounds similar to his name."
> The quip about his name is not an ad hominem because the quip is immaterial to the argument.
That's backwards: ad hominem attacks are considered bad precisely because they're not relevant to the argument. Note that the GP's argument is exactly the opposite: that the attacks aren't ad hominem because they are material in this case.
If you're saying that the original line wasn't meant as support of their argument and therefore doesn't qualify for examination for materiality, I'm finding that hard to swallow too, e.g. "You're wrong, and also incidentally--totally as aside, seriously--you're an idiot."
An insult that is not being used in a logical argument is not an ad hominem, or a logical fallacy of any sort. It is just an insult. This is what I mean by the admittedly poorly stated "immaterial to the argument".
If I say "You are a doo-doo head, and you are wrong because of X, Y, and Z", then (assuming X, Y, and Z are sound of course) I have not committed a logical fallacy (though I have immaturely insulted you). The insult was not a part of the argument presented. If I say "You are a doo-doo, and therefore wrong.", then I am guilty of fallacious reasoning.
Things don't have to be fallacies for them to be out of line. We can criticize "You're wrong, and also incidentally--totally as aside, seriously--you're an idiot." without mislabeling it as fallacious.
Calling him a "whiner", in any form with no substance to back it up is indeed arguing the man, not the substance of his argument. It's also mean, petty, immature, unpleasant to read and I would and have strongly chastised my three and five year old children for this sort of speech and behaviour.
There is no "you should question this because his name is Foo", rather "you should question this because he is acting Fooish, which incidentally sounds similar to his name."
Immature, but not an ad hominem.