I get it if it really hurts your ability to figure out what they are saying. Since the whole point of written text is to convey something. That’s when it does matter. But I don’t think that was the case in that comment and it was quite easy to figure out what they were saying. I’d guess most people reading it wouldn’t even notice it (I didn’t until I saw the rude reply). And when it doesn’t impact understanding what they said, I think it’s really nitpicky to call them out.
He did concede at the end that he was broken and not only was going to say there were 5 lights, he even believed there were 5.