Those horror stories are real. A buddy of mine saw a crew skip steps like brianm66 mentioned and they crossed a fuel line with a hydraulic line. The whole unit was trashed by lunch. Checklists aren't just paper, they're the only thing stopping a rush job from becoming a wreck.
Wait, they crossed a fuel line with a hydraulic line? That's insane. @robertcarr wasn't kidding about a total mess. You'd think that kind of mix-up would be impossible to miss.
A solid pre-job checklist made all the difference for us last year. We almost skipped it during a rush job, but it caught a wiring issue before power-up. Now the team won't start without it... no matter how tight the schedule.