But I didn't open the screen - I'll take a video of this if I have to.
I opened the top lid of the computer, the front of which is a piece of thin flexible plastic - to remove it all I had to do was slide a fingernail between the two halves, even easier than opening something with screws tbh. No screws were touched, no adhesive dealt with and no pressure put on any of the screen. Only a complete imbecile would be able to damage the screen in the process. The whole sheet of plastic just bent forward a bit, I gently wiped at both the smudge of dust and the dead pixels to confirm that they were a problem with the screen and not a liquid or dirt or something between the two layers, and snapped the assembly back together.
If I'd opened the actual unit, ie removed screws or separated any components, I would agree with you, but I didn't, and let me remind you that this problem existed before I did anything with the laptop. I can't prove that of course, but my word should carry some weight, either as a long time member of these forums or as
a trader with many good references behind him.
@deslok see above, yes I had to separate the bezel, but it required no pressure.