1. It is told in a sensationalist way that either is or is close to being orientalism. I believe Feynman was known for his story-telling skills (sometimes with some hyperbole for effect), and I think this case is no different.
2. That said, for someone doing a crash course in Japanese, I can see how this can come across as being confusing... but it's not terribly complicated for a smart person like Feynman. Maybe the teacher wasn't particularly skilled...
3. That said, if Japanese is learned in context over some period of time, using the wrong verb form in these contexts just intuitively sounds wrong to the point that it makes me (and others) reflexively wince.
4. That said, the deeper levels of keigo (not the minor stuff mentioned by Feynman) can actually be challenging to learn, even for Japanese people. This is mainly because the content is unfamiliar since the contexts are not experienced regularly (or ever)... until they are, then the keigo becomes natural.
5. That said, someone like Feynman (and in fact most westerners) would get a pass for using any form of "see" if it is in Japanese. Most Japanese I know have low expectations (rightly or wrongly) for foreigners speaking Japanese, so using the wrong verb form typically doesn't even raise an eyebrow.