From the article

"The lights, which were intended to give the illusion of a sunrise, were placed about 20 to 30 feet from the aircraft, shining on first the right, then the left side of the craft for over nine hours in total.

A foam liner had melted away from at least one of the windows and several window panes appeared to have been warped by the thermal heat. "

It's likely the crew was using fresnel lights which are bright and very hot. You can easily burn yourself or set fire to delicate objects after prolonged use. Not impossible to imagine a crew member moving the lights, leaving them on and highly focused to imitate a distant light source; like a magnifying glass under the sun.

In the article it says the frames were melted by heat from the lights.

I imagine the film crew took out the windows so that they could shine the lights into the plane.

They did discover a missing window pane. They discovered some more too but at least one. 😉

Here's the Instagram account for the article's author. I don't know if she's on lemmy so there's no guarantee she'll see your comment here.

It was probably more cost-effective.

From the photo it looks like the inner window panes were still intact. That would be enough to keep the plane pressurised, I'm guessing. For a while at least.

Less pressure, pretty sure, and if the lowering was gradual enough, you might not feel it. Dunno for sure.

Not with the windows missing the whole time and at 13,000 feet.

A different article I read says Titan Airways / TCS World Travel

Not really. Most planes leak quite a bit anyway- they’re constantly running air compressors to keep it at about the equivalent pressure of 6,000-8,000 feet.

At that point, it was merely mildly concerning. If the window had blown out mid-Atlantic that would have been terrifying- flying low enough to maintain pressure would expend too much fuel, etc. but they were only 10-15 minutes into the flight; so, no big deal.

Also? At 20kft, yiu have about 30 minutes before you pass out. (Airlines typically have 10-15 minutes oxygen reserves, for a fully packed aircraft, more than enough time to dive down to breathable pressures. Even from the normal cruising altitudes of 30-40k ft)

I’m surprised there wasn’t a flashy warning thing, though. At 14k-ish pressure altitude… the oxy masks should have dropped automatically