Both of you are spot on. There would be no boost / positive boost pressure if the Turbo had failed.
I should pay attention when skimming through
what thru me was "Following the pop, for the next 5 minutes home, under any acceleration there was a high pitched whine from the engine bay"
when I have popped an IC pipe in the past I have not had any noise after the initial "pop". to have a noise it may not be off completely or a smaller hose somewhere.
Plus - I did my OP6 Turbo a few weeks back. I heard a PoP and any acceleration I received a whine noise . But your right the gauge did not go over Zero......