While we already knew this was a way to replicate it, I don't think I've seen it this reproduce able on live.
I was getting it on the 4th join, another SPCT got it on 3rd join and yet another test subject got it after 5.
We had QA trying this on dev before I believe, but they weren't able to reproduce it there.
I'll try to get them to try again with the exact steps and settings we were using.