The Wrestler director Darren Aronofsky has said Christian Bale's behaviour when berating a crew member on set was "reasonable".
An audio recording of Bale's rant on the set of Terminator Salvation was leaked earlier this week, with the 35-year-old actor criticising the film's director of photography for walking into his sight-line.
The recording depicts the star of The Dark Knight swearing repeatedly at Shane Hurlbut for compromising a scene involving Bale and Bryce Dallas Howard, with the f-word used 35 times in just over four minutes.
But speaking at the London Film Critics' Circle awards on Wednesday night, Aronofsky said he did not think Bale was "out of line" for the reaction.
"It is a sacred time between action and cut," he told the BBC. "If it was the first time it was excusable, but a second time that ruins it."
Aronofsky, the partner of British actress Rachel Weisz, added: "Sets are very, very high-powered places where things go awry all the time and emotions are high.
"People are out there working really hard and exposing themselves, especially actors, and they need to be protected."
He went on: "Although it's never good to lose your temper that bad for obvious reasons, we don't know what scene he was doing.
"He could have been doing a deeply, deeply intense emotional scene."
Bale has not commented on the tape but Bruce Franklin, the associate producer of Terminator Salvation, came to the actor's defence.
"It was the most emotional scene in the movie," he told E! News.
"He is very intensely involved in his character. He didn't walk around like that all day long. It was just a moment and it passed."