a) The lawyers of that site are obviously biased defending fixubuntu.com , that's what most lawyers do for their clients, is not? so that's irrelevant. They do not have any legal basis to support the way fixubuntu.com was using Canonical's trademark . The "nominative fair use" doctrine they are invoking simply does not applies in this case.
b) My impression is that MS is being misleading here with his statements . I do not think he is saying that fixubuntu.com was right or that Canonical had no the right to protect its trademarks in this case. All he is saying is that " the less-than-a-month-at-Canonical new guy sent out the toughest template letter[...]It was a mistake..." . He is basically saying that they were not friendly enough with that specific request.