Is this the standard of Pizza Hut, Kuching???

I went to one of the Pizzza Hut outlets in Kuching with my friend last weekend, who are originally from Penang, now working in Miri (Petronas) and came to Kuching for a visiting.

When the ordered pizza arrived, my friend discovered that the pan is full of carbon as shown in the photo below:
He told me that he worked in Pizza Hut before, and he knows that this is not acceptable in terms of quality and in fact, it is not healthy to have the pizza together with this carbon. Thus, he asked the manager to our table and ask her regarding the carbon around the pan.

As explains by the manager, old pans always have this carbon around and this is biasa (normal). My friend couldn't accept the answer and ask her did they check and wash the pan before putting it into the oven??? Then the manager said something without any concrete answer and i can't remember what she says since i don't wanna involve into the issue. Then the manager goes to the kitchen and check it out.

After few minutes, she came back, apologize to us and said that she will prepare another pizza for us (for free) so that we can look at their 'actual quality and standard'. After the pizza came, we don't dare to eat with few reasons... (don't wanna mention here) and we left that pizza on the table after finishing our own original pizza.

Did you aware of the carbon when having your pizza in Pizza Hut?