Isn't that story more myth than reality?
The history section of the Wikipedia entry for "bug" [1] suggests it predates computers by decades.
The actual story is not myth. It just isn't the origin of the term.
Hopper's note didn't suggest the word was new, but was funny exactly because it was not.
It's also more moth than reality.
Moths are, technically [0], not bugs.
[0] https://en.wikipedia.org/wiki/Hemiptera