For those not familiar, American Spanish diverged significantly from "mainland" Spanish. Even then Mexican Spanish is quite distinct in its own "charming" way from nearly every other Spanish speaking American country. It's not just the vocabulary, even the verb tenses are used differently in different countries. Case in point, the only time I've heard vosotros used outside of school was in a La Polla Records song (ya ahora que?). Or looking for the baños in the Barcelona airport…. The differences are significant enough it's possible you're both right.
Whenever I've seen language discussed online lots of people come out of the woodwork defending their own niche regional variations. The comments section on Vanity Fair's Slang School series of youtube videos is a particularly obnoxious example. The videos themselves are great IMO. It's not always that bad though. I was trying to figure out how to differentiate between a banana and a plantain in Spanish (yay spanishdict forums) and I didn't realize just how many different ways there are to say banana/plantain. It's like Eskimos and snow.
To be properly obnoxious I'll wonder if that's how those folks were taught to speak/write. In my mind the analogous English situation is when British speakers use me in place of my.
You wouldn't believe the amount of times I was "corrected" with suggestions that were clearly, blatantly wrong if I didn't outright say that I was a native speaker.
I think it was mainly Americans from Spanish speaking immigrant families who were overconfident on their skills, but it was funny nonetheless.