Ha 
You sound like you don’t trust my advice @tobiaseigen
Using the API would be a safer option than the rails console, it’s just not clear if it would successfully undelete this particular topic due to the circumstances.
I wasn’t confident the API would work as trying similar in the UI was blocked, but I seem to have had some success (
).
In this case, I used the endpoint to recover the post rather than recover the topic (which is what the undelete option in the post was trying to do):
/posts/POST_ID/recover