What's fascinating to me is how we all tend to see what we think we see - not what's really there. This isn't about EF... but because, for one reason or another, he has the "eon" spelling in his head - that's what he sees, regardless of what's actually on a bunch of black and yellow jerseys.
The same thing happens - all the time - to writers. If I'm writing up a discussion of a budget proposal (e.g., before I retired!), and in the course of editing, I accidentally type the word "the" twice in succession - I will NOT see it when I go back and re-read the piece. An editor, or a different proofreader, who doesn't already "know" what it says? Hits 'em between the eyes, and soon some junior analyst is ragging me about it! But because i "knew" what it said, I didn't see what it actually said.
Your point about thinking somebody's name is - of course - spelled the same as somebody else's, with whom we're already familiar, is also spot-on. I suspect that's often part of the reason why we decide we "know" how something's spelled, even when we're wrong (and we're all wrong some of the time!).
I've actually been trying to just ignore such things (with middling success?). As y'all probably know, I have a bugaboo about getting "our guys'" names wrong (please, let us never sign Jarrod Saltalamacchia - assuming I spelled that right!), but even then, I've been trying to just move on. I do worry, though, that if a given misspelling appears too often, others will conclude that it's correct, and that will metastasize. Just my personal foible.