They don't know shit, one time when I was trying to buy some this alarm went off. Needless to say I was on so much ephedrine that I almost ran out of the store.
The pharmacist overided it and sold it to me anyway. The last 2 times at a different store they refused to sell. They have no idea why its flagged and they have no idea how I can fix it. 
This is California, BTW.
I’m not sure exactly how the protocol works, but I suspect it’s largely conditional
(at their discretion).It could be as simple as just waiting a while longer to buy more.
Or, perhaps after a “violation,” they make you wait a bit longer.
I sincerely doubt they would deny you from ever purchasing it again.
You saw yourself that they can override an alert.
I doubt your offense will result in anything substantial.
I’ve already talked with people who were never even asked to show their ID when buying it at the pharmacy.