Cindysphinx
G.O.A.T.
I have a friend who does this all the time. He doesn't play tennis, it just happens in real life a lot. He knows this and says that his motto is "Often wrong, never in doubt".
It doesn't bother him. Some people are like that.
I think it's a mistake anyway to yell "switch!". When my partner crosses I know to cover the open court. Yelling "switch" makes me think he believes he has a real dummy for a partner. Only a raw beginner thinks, "But, but...that's MY side of the court! I can't go over there."
If I wondered if the point had been called to an end, I'd also find that to be a hindrance. Playing while wondering if a point is over, is very distracting.
"Switch!" is shorthand for "I've got it. No need to turn around and run to the baseline like your hair is on fire. Don't try to jump up and reach it, because you'll just frame it into the ceiling. Also, by my making noise, I am giving you a clue about where I am on the court so that you don't have to turn around and can instead focus on our opponents."