Unfortunate result, However thats the gamble you take with modding a car.

Plain and simple!

As stated before, taking things on pure blind trust is pretty bad in the real state of things. However having a third party testing the compression results was a good idea to help the feuding workshops in question.

So... faced with an engine rebuild, i guess the upside is that you will be able to finally chuck some new pistons and rings in and get it over and done with first time round. (even tho its a new added cost )