ARSE!
It doesn't how many times you've discussed it with x, y or Z or to what depth you, x and y discussed it. X, y and z have moved on and _I_ need to know the detail of it. I'm not looking for a scapegoat, I don't care whose fault it is, I need the information so that I can access just how BIG a crock of shite I'm now holding. Stop with the blame avoidance tactics and tell me how deep it is embedded in your journeys.
Ok, so maybe he was being circumspect because he's on the train, and you can't really talk in detail about user authentication protocols when surrounded by the great unwashed, but really, do you really need to keep trying to not be at fault quite so blatantly?
It's difficult being a blunt Yorkshireman with overtones of techie related aspergic tendencies when trying to extract information about why it's broken from a marketing leaning politically savvy colleague, no matter how well you get on.