Fireable Offense?

Woman calls a customer service department, complains about something, has the situation explained to her.

She goes on a consumer advocate Website and describes the situation, saying that she had spoken to someone who was "moderately intelligent."

Customer service rep sees this post, takes offense. He uses his customer service email account to send an email with the content "moderately intelligent...?" to her.

She goes on the Website and characterizes this email as outlandish, offensive, etc.

The customer service rep gets fired. I dunno'. On the one hand, the rep's response was clearly ill-advised, but on the other hand, aren't we supposed to be breaking free of old conceptions of the appropriate tone between a company and its clients? If a rep responded, not with a boilerplate "We apologize for any inconvenience..." but with a "You know, that really hurt because I was distracted that day because I'd been up all night hand-feeding some kittens..." then this might have been some example of a company "speaking with a human voice." Is it really a fireable offense to take offense at being insulted (not that characterizing someone as "moderately intelligent" is extreme behavior) and to let the person know that you object?

What do you think?

Update: Chuck Todd has a blog entry complaining about the tight reins he's experiencing as a member of the White House press corps. The most common response of commenters is "quit whining." But I read it and see "These are the conditions I work in. They're frustrating and don't serve anyone's interests." It's the same kind of thing -- a personal tone, but isn't that what everyone's supposed to be doing nowadays?