[anderiv]

That flight certainly did not do any unpowered gliding. With their "20 minutes left" line, the pilot likely meant "20 minutes until we hit our reserve fuel", at which point they would be forced to declare a fuel emergency and land at whatever airport is available.

[hackmiester]

If so, the pilot would have done better to keep his mouth shut. Why the hell would someone say that to a bunch of passengers who are presumably totally untrained in aviation?

[stouset]

Because it makes no sense to assume that the pilots, at least one of whom presumably prefers to continue living, would just circle around to the point where the engines quit?

The pilots are in the same plane as you. They aren’t going to just let the plane run out of fuel because some person on the ground says “sorry, can’t land at this airport yet, hang out for awhile”.

If there was a real emergency they’d be putting the plane down on the nearest runway-shaped surface no matter what.

Further, I’d wager the pilot said something along the lines of “we have twenty minutes of fuel before we need to consider diverting to [alternate airport]” or something to that effect.

[justsomehnguy]

Absence of information is almost always way more scary (and sometimes leads to panic) than the presence of even a little of some.

Maybe pilot wanted to say what there is still enough time for them to keep waiting, but in that situation didn't though how that phrase would sound for the passengers.