Call it an increasing level of cynicism, sophistication or meta-fiction, but there's a growing trend for movies to call out a plot hole than actually trying to pave it over.
This little trope, Hanging A Lantern, keeps growing because film crews figured out that shooting a new line of dialogue is cheaper than re-shooting a scene of plot sealant.
So why do writer's end up Hanging the Lantern when they don't need a film crew?
Thinking about the workshops I've been to, there's three main reasons you have a plot hole.
Part Time Writer:
A person has to eat, so their fiction writing is done here and there, on the train, during lunch, late at night when everyone else is in bed.
Writing in chunks like this leads to the writing forget what ground they've covered before and/or what they have yet to explain.
The cure: A continuity re-draft. This a different kind of rewrite, you don't add a missing apostrophe, or delete an extra comma. You grab a pad of paper and take notes on the plot, character names/spellings and anything else that needs to maintain consistent throughout the story.
The writer has a "vision" or doesn't know how to get to their great money shot of scene without taking a logical path to get there. You're biggest hint: If nine people tell you it doesn't make sense, then the issue might be the story, not your readers.
The cure: Readers you can trust. This is where a good workshop can help you understand that: a.) Your plot doesn't work; b.) How to get there in a believable way.
If your idea of military research is to watch more Hollywood blockbusters, then don't be surprised when your war story never makes it past the slush pile.
The cure: Too often the adage "Write what you know," is taken to literally. If that was a truth instead of a guideline, then The Wire's first season would have had drug dealing scriptwriters. And Elmore Leonord would have never written a crime novel ... or a Western. A little research or having a researcher helps fill in the gaps.