Another possibility is that this tech was somewhere in middle of research queue.
For example you had it selected for research before someone got it.
We could do Nightmare test game - someone should select religious techs among other techs and let AI get them first.
Religious tech should be kicked out of queue if someone researches it in mean time.
EDIT: Its not this case - those techs were kicked out of queue.
So only thing that can happens is you researching religious tech and then AI manages to research it before you.
EDIT: Went couple autosaves earlier and gave myself Animism.
I can still research Shamanism after someone got it first.
I had Druidic Traditions selected as second tech in queue, I still can research it after someone else got it.
So this removal from queue was graphical only.
Here is save, just click away turns.