No national error rate is established. An error in a reference does not by itself prove a law is invalid.
Find the controlling text
Start with the signed law, its amendments and the date it took effect. A web copy may lag behind. Keep each version and its source.
Test the exact claim
Record the clause, the words at issue and the place they point to. Check whether that place exists and says what the link needs it to say. Read nearby clauses too.
A second reader must check the finding. Mark a draft as a draft. Do not count an old error as a current one after it has been fixed.
Show the fix
Publish confirmed findings with scope and limits. Name the office that can fix each one. Keep dated corrections at the top of the case.
Federal and BC correction programs show that repair paths exist. Their existence does not tell us how common errors are. That needs a defined sample and full review.