OK, I've just watched the video (I knew about the viewbots a while ago) and it does seem pretty damning. I know streamers and vloggers get accusations, trolls, cynicism - that's all part and parcel of being in public view or providing content. The fact the real balance is carried to a demo game is impossible unless you're running fake software (this isn't fake) OR by design.
As you may know (not UK IP's any longer) I post video reviews and written reviews of upcoming slots and this includes putting in urls' for visitors to play the demo games. They have different codes from real play url's and the game server/aggregator cannot mix demo and real play up as a result, for obvious reasons.
I cannot see any other explanation here (I haven't got time to be more expansive right now as I've left a task to type this) but the fact the casino interface has been set-up to mean a demo balance can be transferred from slot-to-slot. The casino has the means to do this as you'll all know when for example they identify balances as bonus or withdrawable cash or want to load free spins into their system on certain games. This has all the hallmarks of a specially-integrated account set up for R********n for advertising purposes.
Obviously I anticipate more detailed information from maybe casino reps, @trancemonkey
etc. who can explain it better than me. Luckily I have numerous contacts with many developers and they should be able to confirm the facts regarding this and explain exactly how this can be possible.