Looking at my previous explanation, it wasn't that clear :)

When I said: save whether we found at least one _meta not found and schedule a retry at the end of the loop.
I wanted to say: save whether we *didn't find* at least one `_meta` not found and schedule a retry at the end of the loop. 

Sorry about that. The difference is that if you don't schedule a retry when you found at least a `_meta`, you might be loosing other rivers I'm afraid? There might be some that need a retry? But wait before changing this, I want to have somebody else looking at this too and make sure this is correct :)