Dear jesse,
You can tell yr Boss it's HACCP 101 and open a few of the books on HACCP to prove it.
Alternatively you could suggest buying one more MD to monitor what happens at/after the slicer ? 
Rgds / Charles.C
I agree with Charles. HACCP 101.
I like when people answer a question with a question to answer their own question.
Yeah that's correct. So try this:
Is there metal in the process after the metal detector?
Does the equipment have metal parts?
Is the slicer itself that has direct contact with the food made out of metal?
Is it possible for any metal to get onto/into the bread after the metal detector?
Are you a
?
H.E.D.