I'll bet if you read the fine print the dot gov site says something like this:
"This site is maintained...[yadda yadda yadda]...only the copy of the [insert regulation name here] maintained by by the legislative recorders office is official"
Oregon's legislative site, where we access our regulations, has this disclaimer:
The text appearing in this database was produced from material provided by the Legislative Counsel Committee of the Oregon Legislative Assembly. The official record copy is the printed published copy of the Oregon Revised Statutes. The text in the database is not the official text of Oregon law.
Although efforts have been made to match the database text to the official legal text they represent, substantive errors or differences may remain. It is the userís responsibility to verify the legal accuracy of all legal text. The State of Oregon is not liable for any loss or damage resulting from errors introduced into the materials supplied by the Legislative Counsel Committee, by a user or any third party, or resulting from any defect in or misuse of any search software, drivers or other equipment.