This is the first time I've done these metas in a few months.
I did the entire oil flows meta the first time. Later, when working on my story on one of my characters, I was up to the blowing up the tanks to get the parts bit (not instanced) at the same time as people were doing the oil flows meta. I was at the SW pump area. As the meta was pulling NPCs towards me (e.g. hydra that isn't normally there) and as the pump looked a bit low on people, I helped kill a couple NPCs and also helped them pick up oil. After that part of the meta had finished, I went back to working on the story.
The problem is, I still have the special action key "Oil Reclamation Pump" and a partially filled gauge over my head.
I haven't yet logged out and logged back in again, which should clear it.
Reporting as a possible interface bug.