After watching this I kind of disagree. Wales said he didn’t care multiple times. Calling it the “dumbest question” is childish, yes. Walking out of an interview that was going nowhere is not childish.
I personally think writing Sanger out of Wikipedia history (as in this 25 year celebration montage thing) is quite lame. But I also think pressing Wales on this when he says “you can say whatever you want” is also quite lame. No one is obligated to sit with an interviewer while the interviewer tries to pick a fight.
You missed the part where Wales called a fact an "opinion". Wales could have said "I don't dispute the facts of that case. I see myself as the founder, but I won't argue against other interpretations. Lets move past it." Instead he immediately became defensive, even angry.
The interviewer is right to press on the basic facts and Wales was wrong to ragequit, especially since the exchange lasted less than 45 seconds(!)
I don't see this as a political victim issue: I can see Sanger as an asshole while also seeing Wales as weak.