From what I can gather, it wasn’t the first time it had happened. There are a lot of other details we don’t know about the incident, but I’d guess that this kind of thing happens all the time, on virtually ever movie set. Even though it’s better than most jobs, acting is still a job and some actors take it very seriously, just like some of us take our jobs way too seriously. So give Bale the benefit of the doubt. Maybe he had a bad day or was tired, or was frustrated or whatever. However, if he ever does or says anything like that to you, make sure you give him a right-cross to remind him not to do it again.