According to people around the Internet, the husband is still in the wrong because he was "rude" to the wife. Apparently, anything short of "I'll get it to you when I'm finished this match" or "I'll ask Mike over the internet in this game we are both playing right now" is entirely unacceptable.
There are people seriously arguing that he was being "dismissive" despite the fact that, by definition, that requires actually dismissing someone. Was her mistake reasonable? Yes. Is it his fault? Arguably. Is "what's really important" that he appeared to be ignoring her? No, it's second to the question of whether he actually ignored her.
Trying to claim that the appearance of dismissiveness is more important than whether there was any actual dismissal going on is moving the goalposts. Ironically, I've had and seen arguments with people where they do the same thing. Once their interpretation of something is proven wrong, they try to argue that it's wrong to merely give the appearance of such, and never really admit they were wrong.