The English is a little confusing - "they fired me for allegedly taking pictures or videos — but they didn’t know, because no one saw it" implies she admits she did take pictures/videos of the dead colleague but Amazon couldn't have known.
If she had had taken photos and shared them with police to prove an accident or bad working practices fair enough, but otherwise I think I would have sacked her too if there was even anecdotal evidence that she had taken photos.
i think it was not intentional
e: (because she is only denying the existence of evidence and could just as easily deny the claim itself)
“That is actually what the judge said: that there is a conflict between labor and employer, but the conflict cannot be an argument to dismiss union members.”
But even if it's the former, so what? Assuming she was taking those pictures and videos with the intent to document what was going on in case there was something improper, Amazon absolutely should not be permitted to fire her because of it.
Even if she was taking pictures because she's a gossip and wanted to share them with people because it's just generally shocking to see someone die like that... well, I'm still sympathetic to the idea that she was actually fired because she was complaining about the working conditions, and the pictures she took were just a convenient excuse.