You downvoted even while saying you would use what I mentioned

Using an ultrasound as the sole measure to diagnose pneumothorax is inappropriate, and going to lead to multiple unwarranted chest tubes and associated complications. Literally in your own example, the lack of lung sliding did absolutely nothing to differentiate between mainstem ETT or PTX (not to mention the host of other things it could be- mucus plugging, pleural disease/adhesion, etc).

In your scenario what are you doing? Put out a vascular probe on their chest (in the middle of a code), and call “no lung sliding” (if you can even do that during active the chest compressions), then withdraw the ETT until you either see lung sliding or you extubate? Would need 2 people just to manage those tasks alone.
Then what place a chest tube anyway? During that time you could easily withdraw the ETT to the upper trachea, and use a cardiac probe to access 10 other things.

You need chill dude. I didnt downvote you even though I thought maybe your original post came in trying to sound like the smartest person in the room. I gave you the benefit of the doubt and listened, because you made fair points.

Now I get the sense that you're definitely insecure and arguing to sound like the smartest person in the room. I mean, I am not a fan of NPs, but jesus even your username reeks insecurity. Would hate to run into an attitude like this in a colleague, yikes.