Test for crack in case?
 

Some know my story, but here is the short version. Took my car to a reputable indy to have my oil leak addressed. Car was there about 2-3 weeks, didn't care about time frame as I couldn't drive it anyways. Was told that they needed to borrow a special tool from Porsche to diagnose whether I have a crack in my case or source the location of the leak. Was told that I had a crack in the passenger side of my case where it seals together. After excessively cleaning and tearing apart most of my engine, I still have yet to see the crack. I did notice leaking from the valve and timing chain covers, but nothing from the case.

1. Does anyone know what type of special tool this is? What it does? Is it real?
2. Have not taken off the heater exchangers yet as the engine is on a cart, not a stand. Could the case be cracked somewhere that the exchangers are hiding it?

I want to believe the indy since I have known him for a long time and his reputation is outstanding, but having some doubts my case is cracked.

I would think a quick dye-penetrant test will show the crack if there is one.
Does not require disassembly (other than to get to the area in question).
Simple test procedure...clean area with varsol or simple green etc....spray on penetrant (usually red in color)...wait a bit...spray on developer (clear)...wait a bit...any cracks show up as green lines.
Ask about this with your mech.
Bob