I don't mean to be a downer, but you could certainly cause an accident by calling out an observation which was faulty. I agree with the sentiment that you should speak up when you see something amiss, but let's not kid ourselves that, like every decision, it comes with inherent risk.

I wonder how many people have died throughout history due to embarrassment, or (similarly) going against your instinct. The number exists but is unavailable to us.

- Not having that dark mole near your privates checked out.

- Not wanting to turn the car around.

- Not walking away when those shady guys walked in.

...