Conveniently over-engineered air ducts and lawsuit-waiting-to-happen fire sprinklers are not the only pesky details that throw me out of a story. The unbelievable lack of narrative respect for the fragility of human skulls and brains also makes me forget about whatever the characters are supposed to be doing to fret about hematomas instead.
You've seen the scene: Our Heroes are breaking into or escaping from Evil Schemes, Inc., and run across some hapless guard who has no idea what horrors he is guarding. Since Our Heroes are GoodTM, they simply knock him over the head with a lead pipe and mutter something like, "He'll have a wicked headache when he wakes up, but he'll be fine."
Um. Maybe. Or maybe he now has a severe intracranial bleed, and his brain is swelling dangerously. Bashing someone in the head so hard that they fall instantly unconscious is not like sending them to bed with chamomile tea and the soothing sound of waterfalls, turns out! Maybe he'll be fine, and maybe he'll have mild cognitive difficulties for a few weeks, and maybe he'll be in a coma, and maybe he'll die. Just how well did you calibrate the strength of your skull-bashing heroics, exactly? Are you sure you can be that precise?
And this could be a great plot twist! Our Heroes run around doing heroics, confident that they only kill really bad guys, only go home after a night of adventuring to find their neighbor frantically rushing out the door to the hospital because her brother, the hard-working night security guard who's been helping her pay her kids' medical bills, is in the hospital with severe head trauma after being viciously attacked by an intruder at the warehouse he was guarding. Character growth ensues! Perhaps Our Heroes decide that fighting some Head Honcho Bad Guy isn't enough if they really want to do good, and they need to help people like this security guard and his sick nephew too if they want to change the world, and this affects the plot as well. Maybe they even try things like recruiting ordinary people to Team Good instead of maintaining the Action Hero Masquerade where you're always too busy and everyone else is too uncool and panicky to tell people that oh, by the way the CEO of Evil Inc. is poisoning your water and planning to let their pet alien eat your children for midnight snacks.
Or maybe instead, during the planning scene they discuss ways of getting around the guards, and discount "bash them over the head" as too dangerous and cruel, and have to come up with something more creative.
Just so long as it isn't giant air ducts ;-)