Defendant Nima Momeni took the stand in his own defense Wednesday, in a move that could prove damaging to the defense, depending on how his cross-examination plays out.

On the witness stand Wednesday, Momeni spoke about being "unsettled" and somewhat "upset" about his sister having taken multiple drugs at the apartment of Jeremy Boivin — a friend of Bob Lee's who has been called his drug dealer. But, he claimed, by 9 pm that evening he no longer believed that his sister had been sexually assaulted — and he believed it was just her being dramatic.

Another friend who was with Lee most of that day before he died testified to overhearing an angry phone call come in from Momeni, in which he was grilling Lee about the events of that day, prior to his going over to Khazar Momeni's condo to sort things out.

Khazar Momeni testified that Lee and her brother were acting like best buds at her house, joking on the couch and talking about going out to a strip club together — leaving out the detail, perhaps, of why Lee had even come over at around midnight in the first place.

Lee was in town for the weekend last April, ostensibly on business but it sounds like there was a fair amount of partying going on, after he had somewhat recently relocated from SF to Miami. He was staying at the One Hotel on the Embarcadero. He and Momeni can be seen on surveillance video exiting Millennium Tower together around 2 am, with Lee holding a beer in his hand. The two got into Momeni's BMW.

Momeni said Wednesday, as the Chronicle reports, that while driving with Lee, Lee was making strange noises, spilled his beer, and they pulled over "because I thought he was going to puke." One of the puzzles with the defense's theory of the case had to do with why Momeni drove Lee to a darkened area beneath the Bay Bridge in the first place, so this would appear to be the explanation.

Momeni then says he made a "bad joke," which wasn't much of a joke at all, that set Lee off, and Lee went from "zero to 100" and attacked him with a paring knife pilfered from his sister's kitchen.

As KTVU recounts from the testimony, Momeni says he told Lee, "If it was my last night in town, I'd go hang out with my family instead of fucking around in strip clubs." This, Momeni claims, was enough to bring out the flash of aggression that the defense claims Lee exhibited, brought on by drugs and alcohol.

The story certainly has flaws — this is the first we're learning of Lee coming to see any family in town, but NBC Bay Area notes that was part of his trip, and prosecutors say Lee had a good relationship with them. This storyline also, perhaps inadvertantly for the defense, exposes Momeni's judgmental feelings toward Lee. And given that Momeni admitted on the stand that he also did drugs in the car with Lee, and given that he has a history of collecting knives, can't the whole aggression theory just be turned back on him?

Momeni further claims that he tossed the knife away, over a fence, to keep Lee from retrieving it, and says that he casually strolled away because he didn't think Lee was hurt.

"Your story is that this prominent, beloved, respected man, he wanted to kill you over a dumb joke?" asked prosecutor Omid Talai during the beginning of cross-examination, per KTVU.

"I don't know why the events took off like that," Momeni replied, adding that of all their jokes that night "That's the one he took to heart."

To which Talai quickly quipped, "He did take it — to the heart," referring to the stab wounds.

Bob Lee's brother, Tim Oliver Lee, spoke to the Chronicle outside the courtroom, saying of the story, "I don’t believe it, and I don’t think that makes sense to the jury. They’ve had 18 months to come up with something, and this is the best they have? It’s ridiculous. Bob would never pick up a knife."

He added, of Momeni, "You look at his stature. He’s a bully. My brother was a doughy tech guy. … How do you stab someone three times and not know he’s injured?"

Speaking to KTVU, the brother said of Momeni, "Just seeing him get angry and stuff on the stand, I feel like that's what my brother saw that night. Seeing him get angry."

Momeni's cross-examination continued on Thursday morning, and per NBC Bay Area, some exchanges between Momeni and Talai grew heated. Talai asked Momeni just how angry a brother could get if he found out his sister had been sexually assaulted.

This is a developing story.

Previously: Nima Momeni Takes the Stand In His Own Defense In Bob Lee Murder Trial