Now you have put out a phrase without giving any evidence. I believe you or your ABAPer is wrong here, maybe just does not understand how to use a BADI.
And before asking you should do a search, it is a rule in SCN, and it is the biggest asset a consultant should have.
this search term returns more than a 1000 hits in SCN, and is this search term really something you could not have put together: material master enhancement exit