In most industries where lives are on the line, not using process checklists and multiple reviewers is considered unthinkable. In those, reviewers are often actively encouraged to criticize people of much senior status when they fail to perform basic duties.
Meanwhile, in corporate IT: Most firms use file hosting systems with built in code review functionality. Thankfully, changes often require at least another pair of eyes to approve them. And yet, these are more often than not a formality. Approval is given without actively engaging with the difference in functionality before and after, often within seconds of opening the code review’s URL.
Some of this might be understandable. A junior developer new to a codebase might not think they are in any way qualified to actually approve anything. A senior developer may have a reputation for good work. Other human factors might come into play.
And all of it at one point or another will generate excess cost. Sooner or later, some not well thought out code will go into production, and cause outages[1].
Something that might prevent these is to encourage everyone, no matter how experienced, to participate actively in code reviews. This means, at a minimum, asking questions:
Often enough, code that produces negative side-effects has a certain “funky look” to it. If something seems unclear, unnecessary, out of line, or in some way dubious, this is an easy way in to leaving a comment along the lines of “What’s this do?”
“Clever hacks” - that is, anything that takes longer than expected to understand - should have comments documenting intended behavior. If they are missing, here is another way in.
Last but not least, when you see someone using a pattern you are not yet familiar with, you could ask where (which language, perhaps) this comes from.
This document will give you some ideas. But first and foremost, it gives you the license to question. At the price of a duty to perform code review.
[1] The author of these lines has produced these effects often enough, “for research purposes.”