It is possible that the informant was only confused (or lying) about some of the details they provided for the record. There may be other details that are entirely correct. That may be because the informant actually had first hand knowledge of those details or those details were not a part of the lie.
Any document can contain pieces of information that are true, pieces of information that are false and pieces of information that are somewhere in between.
Don't remove a document from consideration only because a few parts of it are known to be incorrect.