Actually, according to that article:

"A U.S. citizen was arrested under the state's controversial new anti-illegal immigrant law overnight in Tulsa County, an opponent of the law said Thursday."

and:

"Edwards said he wasn't aware of anyone being arrested in Tulsa County for breaking HB 1804 as described by Rivera."

Unfortunately I can't find a direct article, but it turned out that the arrest described in this article proved to be a rumor and no actual arrests have been made.