I'm sure that you all recall Pierre Chang mentioning "the incident" in The Swan Orientation Film from 1980. If the generally accepted timeline is correct, we know that the newest Comic Con video was filmed in 1978, The Swan video was filmed in 1980, and The Purge occurred in 1993. I know that a number of people have noticed that in the newest Comic Con video, Chang looks down at his arm when he mentions The Purge. So, here's my theory...
Remember in "Live Together, Die Alone," when Locke and Eko were fighting to push the button in The Swan Station? All of the metal objects in The Swan were magnetically attracted to the doors and large metal structures inside of the hatch. What if "The Incident" was also something like this? Someone, at some time between 1978 and 1980, hesitated to push the button. Pierre Chang was, at that exact time, in The Swan Station. When the electromagnetism took hold of the hatch, metal objects became magnetized to the metal doors and metal structures it contained. Perhaps some sort of sharp and metal object became airborne and sliced Chang's arm off? This would explain 1) why Chang felt the need to make a new Swan Orientation Film following "The Incident" and 2) why Chang appears to have a prosthetic arm during said film.
In the case that the button did not exist before 1980 because the electromagnetic anomaly did not exist at the time, consider the following. The Swan station was first built to conduct the same psychological experiments Chang claims it is used for in the orientation film. At some point in time, while Chang was in The Swan Station, the electromagnetic anomaly FIRST occurred, prompting "The Incident," the loss of Chang's arm, and finally, causing the Dharma Initiative to use The Swan station to harness the electromagnetism every 108 minutes by pushing the button.
Either way, I think Chang losing his arm has something to do with "The Incident" and The Swan Station.
Theory by Angelica
Remember in "Live Together, Die Alone," when Locke and Eko were fighting to push the button in The Swan Station? All of the metal objects in The Swan were magnetically attracted to the doors and large metal structures inside of the hatch. What if "The Incident" was also something like this? Someone, at some time between 1978 and 1980, hesitated to push the button. Pierre Chang was, at that exact time, in The Swan Station. When the electromagnetism took hold of the hatch, metal objects became magnetized to the metal doors and metal structures it contained. Perhaps some sort of sharp and metal object became airborne and sliced Chang's arm off? This would explain 1) why Chang felt the need to make a new Swan Orientation Film following "The Incident" and 2) why Chang appears to have a prosthetic arm during said film.
In the case that the button did not exist before 1980 because the electromagnetic anomaly did not exist at the time, consider the following. The Swan station was first built to conduct the same psychological experiments Chang claims it is used for in the orientation film. At some point in time, while Chang was in The Swan Station, the electromagnetic anomaly FIRST occurred, prompting "The Incident," the loss of Chang's arm, and finally, causing the Dharma Initiative to use The Swan station to harness the electromagnetism every 108 minutes by pushing the button.
Either way, I think Chang losing his arm has something to do with "The Incident" and The Swan Station.
Theory by Angelica