I think the simpler way to think about this is that it's definitely possible (and common) to use words confusingly.
That is, you can use words in such a way that many people misunderstand what you mean. You could then call that usage "incorrect" if you want, and I wouldn't quibble too much with that, but the more important reason not to use those words in that way is that people don't understand you.
But in this case, this usage of "in real life" is not confusing anyone. Even those who pedantically quibble with it being "wrong" actually understood what was meant.
That is, you can use words in such a way that many people misunderstand what you mean. You could then call that usage "incorrect" if you want, and I wouldn't quibble too much with that, but the more important reason not to use those words in that way is that people don't understand you.
But in this case, this usage of "in real life" is not confusing anyone. Even those who pedantically quibble with it being "wrong" actually understood what was meant.