Nickelodeon Star Denies Driving Drunk

As TMZ first reported ... Ryan was arrested on July 8 -- minutes after leaving Dillon's Irish Pub where he partied with Zac and Rumor Willis.

During Rottman's arrest, Efron -- who was still hanging out in the area -- was seen pacing around on his cell phone.

Law enforcement sources tell us ... Rottman's blood alcohol level was .19 -- more than twice the legal limit.