In need of some help!

Earlier in the year I had my 1.6 centre section replaced in stainless steel to match my backbox.
Now part of my cat has snapped just underneath it.

Now I trust my mechanic but he is saying aswll as the cat he will have to replace the the centre section aswell, due to the fact where its hit the floor there's a hole in it.

The hole is on the bend upward towards the cat just after the bolts.

Just wondered if this sounds correct to anyone? As I thought it would just be the cat that needs replacing and I didn't see a hole when I was underneath securing it back up.


Thanks!