Peer review isn't (and never was meant to be) a golden seal declaring a result to be unchangeable truth. It is a process that makes sure that at least one competent colleague has read it and caught all the embarrassing Monday morning mistakes that might have been in there. This is done before wider publication to avoid that the 100 people in your field all stumble over the same stupid little mistake and can spent their time thinking about the actual content.

Think of it as the type checking by the compiler or a code review by somebody on your team, NOT a papal announcement of unchangeable dogma.