Though the younger brother of Michael Jackson's accuser told a compelling story about seeing the pop singer molest his sibling on Monday, his testimony started to fall apart during cross-examination Tuesday (March 8).

Fidgeting with his hands, the boy acknowledged he was nervous, telling the court Jackson gave them a warning "not to tell anybody what happened, not even if they put a gun to your head." Then he tried to answer questions by Jackson's defense attorney Thomas Mesereau, who poked several holes in the boy's testimony (see [article id="1497854"]"Witness: I Saw Michael Jackson Molesting My Brother"[/article]), pointing out inconsistencies in his story as well as bringing up previous mistruths that could undermine his credibility.

On Tuesday, the boy admitted to lying during a deposition for his mother's civil lawsuit against J.C. Penney, in which he swore under oath that his father never hit him. He said he didn't remember why he didn't tell the truth, because it was five years ago. The father pleaded no contest in 2001 and guilty in 2002 to charges of domestic and child abuse (see [article id="1480656"]"U.K. Reports Tell Story Of How Jackson Met His Accuser"[/article]).

The boy had said under direct testimony on Monday that there was a red ring around the 7-Up soda can he saw his older brother drinking from in Miami, implying that there was wine in it. Mesereau pointed out that in the past, the boy had testified that there was white wine in the can. The boy said the court reporter must've gotten it wrong.

Mesereau also questioned the younger bother about the Barely Legal pornographic magazine that he testified the singer had shared with them, showing him a copy of the magazine and asking him if he was sure. When the boy said yes, Mesereau pointed out the date on the magazine was August 2003 -- months after the family said it had left Neverland.

"That wasn't exactly the magazine he showed us," the boy responded. "I didn't say that he showed us that exact one."

Mesereau also grilled the boy about his previous claim that Jackson never let them look at clocks, saying "it defies common sense." "There are clocks all over Neverland," the lawyer said, but the boy said the clocks told conflicting times.

Though the defense contends the brothers memorized security codes to enter the wine cellar and other areas without permission, the younger brother said the cellar could not be opened without a key and that he didn't know where it was.

However, he also said there is an alarm system that triggers an electronic bell when anyone climbs the stairs to Jackson's bedroom, and that it had rung both times he claimed he was in the hallway observing the singer touching his brother, which would imply that Jackson heard someone coming and did not stop.

(CBS News contributed to this report.)

For full coverage of the Michael Jackson case, see [article id="1480530"]"Michael Jackson Accused."[/article]