Cored hull? 1999 3300 SCR?

[mkl101]

So I have my boat 1999 3300SCR up for sale. Potential buyer asked that it have a presale in and out of water inspection not a full survey. The guy doing the inspection tells me there is 5 soft spots in my bulsa cored hull? Everything I find online states its not cored hull and a solid fiberglass hull. If that's the case how possible is it that solid fiberglass has gotten soft spots? He was basically doing a tap test where you could hear the difference in the sound of the hull out of water.

Needless to say he contacted the buyer last night and the sale is off. I'm really hoping that he was wrong and a normal surveyor can check the boat over correctly and give me better results.

Thanks
matt