That looks to be an FP compressor housing not the usual Garrett piece...

 

That's the Tial Alpha compressor housing. They have a few sizes depending on which compressor is used. Built to support the Alpha compressor wheels modded on the Garret turbochargers.

 

That sucks! The good news is I'd be very surprised if any part of that made it through your intercoolers to your engine.

 

I blew a wheel to bits, looked like a bird strike into a turbine on a jet plane gone bad....intercooler stopped al of them. I needed a new intercooler (have to make sure NO parts get into the engine). Mine was caused by a similar issue (shop that was working on my Mitsubishi screwed up). They paid for 100% of the repairs! I hope your shop is being as accommodating.