I don't know what they(who ever they are/is) were doing with telling you they were going to outsource the o-ring from some auto parts supplier.
Firstly this bike is under warranty, and should be repaired in the spirit of industry best practice with genuine parts. Especially fuel system components that are under pressure.
Secondly the O-rings on injectors (in my experience) are never ever available by themselves (hence no individual part number) and are always replaced along with the injector. There are a number of extremely good reasons for this.
Thirdly if what you have relayed to us is accurate, I think there's good reason to doubt the competency and experience of the dealer if they're actually prepared to take the original course of action. It sounded dodgy to me from the start.
I wonder if it was garbage information that you were being fed by some ........ so-called service manager who wouldn't know their hat from their ........
