More info from The Independent:
According to US media reports,
the taped incident, which took place in July, was considered sufficiently serious for the film's producers to pass a recording of Bale's outburst to their insurer, amid concerns that a walkout by Bale would threaten the production. It seems to have then found its way into the public domain after being leaked to TMZ by an employee of the insurance company.
Many Hollywood commentators said Bale's outburst was a proportional response to an unforgivable lapse by a technician. "Hurlbut walked across Bale's sight-line during a scene," wrote Geoff Boucher in the Los Angeles Times. "That's a huge no-no. I'm not sure anyone in Hollywood will be surprised by this eruption, except by its duration."
Star's tirade against director of photographyChristian Bale: Am I going to walk around and rip your fucking lights down, in the middle of a scene? Then why the fuck are you walking right through? Ah-da-da-dah, like this in the background. What the fuck is it with you? What don't you fucking understand? You got any fucking idea about, hey, it's fucking distracting having somebody walking up behind Bryce in the middle of the fucking scene? Give me a fucking answer! What don't you get about it?
Shane Hurlbut: I was looking at the light.
Bale: Ohhhhh, goooood for you. And how was it? I hope it was fucking good, because it's useless now, isn't it?
Hurlbut: OK.
Bale: Fuck's sake man, you're amateur. McG, you got fucking something to say to this prick?
Joseph 'McG' McGinty Nichol (director): I didn't see it happen.
Bale: Well, somebody should be fucking watching and keeping an eye on him.
McG: Fair enough.
Bale: It's the second time that he doesn't give a fuck about what is going on in front of the camera, all right? I'm trying to fucking do a scene here, and I am going "Why the fuck is Shane walking in there? What is he doing there?" Do you understand my mind is not in the scene if you're doing that?
Hurlbut: I absolutely apologise. I'm sorry, I did not mean anything by it.
Bale: Stay off the fucking set man. For fuck's sake. Alright, let's go again.
McG: Let's just take a minute.
Bale: Let's not take a fucking minute, let's go again.
Bale: I'm going to fucking kick your fucking ass if you don't shut up for a second! All right?
(Unknown voices): Christian, Christian. It's cool.
Bale: I'm going to go... Do you want me to fucking go trash your lights? Do you want me to fucking trash 'em? Then why are you trashing my scene?
Hurlbut: I'm not trying to trash your scene.
Bale: You are trashing my scene!
Hurlbut: Christian, I was only...
Bale: You do it one more fucking time and I ain't walking on this set if you're still hired. I'm fucking serious. You're a nice guy. You're a nice guy, but that don't fucking cut it when you're fucking around like this on set.
http://www.independent.co.uk/arts-entertainment/films/news/bale-turns-american-psycho-with-expletiveladen-tantrum-on-set-1544988.html