I experienced to work with the code which was reviewed, but still of low quality. Actually reviewer looked through the code and could think that this is more formal procedure and didn't pay enough attention to the process of review and said: "I have reviewed the code!". Some small fixes can be made but significant flaws are missed.
The problem is to explain that it is important to make the thorough review, because in future this code is easier to support, extend, fix, easy to reassign to other person etc...
But all these reasons are not essential for reviewer. Responsible for code is another person. Oh, author of code can leave company? Reviewer didn't think about this. Company spend more time to fix bugs when they reproduced by tester? it doesn't mater for reviewer. Some things are not documented? Author explain this to the reviewer. And reviewer even can support effectively such code. others... others...