Sure, even the most professional of garden enthusiasts may misidentify a plant. Go into a reputable nursery and you're insured of correct identification. Right? Wrong! Look on the Internet and a web page certainly has enough people browsing that all the mistakes have been corrected. Right? Wrong. Listen to an old timer and take it for gospel the name of a certain plant is such-and-such. Right? Wrong.
At plant stores, tags may be removed by the far sighted shopper and replaced on the wrong plant. Or, the seeds from their source may have been in error. I was the victim of that this year. Last year I had enough butternut squash that people refused to take more. I still have squash puree in my freezer. This year I wanted summer squash to add to salads and my tomato juice. It was planted, it has thrived, it is butternut squash. Rats!
The Internet (as always) is only as good as the source typing. It is "rife" (always wanted to use RIFE) with mistakes; even information gleaned from places that have their own botanists and experts. It's just human nature to get some information wrong or to have information transferred incorrectly.
Old timers (and most gardeners will eventually fall into the old timer category) often use localized or folk information for plants. This blurs the lines of horticulture correctness. With the way people move out of their native born areas more often than in the past & Internet accessibility, that information moves across the world.
The attributes of plants may also be incorrect; having been incorrect years and years ago but refusing to give up to new research. That's the whole folklore thing. "Grandma said goldenrod makes her sneeze and so it must cause my allergies today." Research proved it is not goldenrod but ragweed making some of us suffer although they bloom at the same time.
If you really care about the identity of plants (say for research, hybridizing, or you're that way), check several sources and take the average. As for misidentified nursery plants, you could go back and ask for them to make it right. Although by the time you realize the mistake, it's too late to make it right in your garden. SO, anyone want a butternut squash - cheap???? Really cheap!!