This was a scam from the start. They fucked themselves because their trailer was popular and they promised the world. Their goal was to create a shit early access game with pre-made assets, get lots of buy in when it was released, endure some bad reviews, promise to fix things but then slowly dump support for the game. I've watched this exact thing happen probably ten times now.
What killed them was the hype and popularity. They were called out immediately for what they were doing and got stuck having to now make an actual game or face legal repercussions.
At the very least these cash grabs are getting spotted early and they're not getting to sneak by without facing consequences.
I work as a hospital supervisor. I honestly don't know of any facility where you can't get saline iv flushes. Most nurses have pockets full of them each shift. If you didn't have that for some reason you could get sterile saline and draw it up yourself, also would be easily obtainable.
My only thought here is that the person didn't want to leave the room when administering drugs and so they used tap water as an easily sourced replacement for the drugs they was stealing since there is a sink is every room (at least in most hospital rooms).
The real answer here is that drug addiction overrides rational thought and they either didn't know or didn't care that tap water is not safe at all for iv administration.
We see lots of cases of diversion unfortunately because these drugs are just so damn addictive and there are only so many safe guards you can put in place to protect against it. At the end of the day no matter how many checks there are you will eventually have a clinical staff member drawing up the drugs and administering it. As long as this remains the case you will have people that abuse that weak link in the chain.