The police document says the tipster tried to provide a reality check to robbery suspect Anthony Michael Carleo by telling him, "Dude, you watch Ocean's Eleven too much. This is real life and that doesn't happen."
Instead of listening, Carleo, the son of a judge, went ahead with the holdup then quickly gambled and talked his way into jail, the report states.
Carleo, 29, made his first court appearance Monday since being taken into custody. He spoke only twice and was not asked to enter pleas on six charges, including armed robbery, assault, burglary and carrying a concealed weapon.
"I did, your honor," Carleo said when Las Vegas Justice of the Peace Ann Zimmerman asked if he understood the charges.
Carleo, shackled and dressed in a blue jail uniform, also said he preferred to use the last name Carleo instead of the last name of his father, Las Vegas Municipal Court Judge George Assad.
Carleo's lawyer, William Terry, declined to comment after the hearing. Another hearing was scheduled Feb. 23.
Surveillance video from the Dec. 14 heist shows a motorcycle helmet-wearing robber waving a gun as he ran from the Bellagio.
The unidentified tipster later contacted police, saying Carleo had speculated that he could off-load individual chips valued at $25,000 and gamble the rest at about $5,000 a month, according to the arrest report.
Bellagio records show Carleo had little restraint, losing about $105,000 during 18 gambling sessions in just over a month, including $72,000 on New Year's Eve.
He also tried to sell chips to Matt Brooks of Washington, D.C., a stranger he contacted through a popular Web forum for poker players, sending pictures of $25,000 chips with a note signed "Biker Bandit," Brooks told law enforcement officials.
About $1.2 million of the loot has been accounted for, police said.
Carleo was arrested after an undercover police officer bought stolen chips and invited Carleo to be part of a crew that would rob Las Vegas casinos, the arrest report said.
Carleo told the officer he had already robbed the Bellagio, the report said.