The purpose of this thread is to have a bit of fun with mistakes by explaining why they weren't actually mistakes, as per traditional No-Prize rule.

Here are the rules:
You can find errors from any era, including ones that actually earned No-Prizes.
You can't scan the letter pages or Handbooks for previous explanations and knowingly claim them as your own.  It is possible, however to accidentally come up with the same explanation that was used in a letters page, as long as you come by it independently.
You can try to improve upon (or go in a different direction) an explanation that's already presented in either official materials or here.
If you have no answer, you can just post the error and challenge everyone else for an explanation.

I'll start with one of the most infamous examples:
Tales of Suspense #92. Cap says, "Only one of us is gonna walk out of here under his own steam -- and it won't be me!"
I think for this one the simplest explanation works best: He got a bit tired during the fight and made a slip of the tongue. His opponent was a robot and likely lacked the sense of humour to mock him.

Marvel Superhero Contest of Champions #3: The contest ended in a tie but gave the win to the Grandmaster.
The Handbooks give a good explanation (ties favour the Grandmaster) but I'll go with: The Grandmaster and his mysterious opponent conducted a fifth round on the Squadron Earth (the Grandmaster having a certain affection for them having used them in his schemes previously) and this unseen fifth round broke the tie.

Fantastic Four #17: Invisible Girl claims to Doctor Doom that Reed is one of world's foremost judo experts, something that wasn't seen since.
Me: This was pretty early on in Sue's career and Doom is pretty tough. Put simply, she was bluffing.